Motorola ASTRO XTSTM 4000 Detailed Service Manual

ASTRO

®

XTS
Portable Radio
Detailed Service Manual

TM

4000

Title Page

ASTRO® XTS™ 4000

Digital Portable Radios

Detailed Service Manual

Motorola, Inc.
1301 E. Algonquin Rd.
Schaumburg, IL 60196-1078 U.S.A.

6871620L01-C

Foreword

The information contained in this manual relates to all ASTRO® XTS™ 4000 digital portable radios, unless otherwise
specified. This manual provides sufficient information to enable qualified service shop technicians to troubleshoot and
repair an ASTRO XTS 4000 digital portable radio to the component level.

For details on the operation of the radio or level 1 or 2 maintenance procedures, refer to the applicable manuals, which are
available separately. A list of related publications is provided in the section, “Related Publications,” on page x.

Product Safety and RF Exposure Compliance

Before using this product, read the operating instructions

!

C a u t i o n

This radio is restricted to occupational use only to satisfy FCC RF energy exposure requirements.
Before using this product, read the RF energy awareness information and operating instructions in the
Product Safety and RF Exposure booklet enclosed with your radio (Motorola Publication part number
6881095C98) to ensure compliance with RF energy exposure limits.

For a list of Motorola-approved antennas, batteries, and other accessories, visit the following web site
which lists approved accessories: http://www.motorola.com/governmentandenterprise

for safe usage contained in the Product Safety and RF
Exposure booklet enclosed with your radio.

ATTENTION!

Manual Revisions

Changes which occur after this manual is printed are described in FMRs (Florida Manual Revisions). These FMRs provide
complete replacement pages for all added, changed, and deleted items, including pertinent parts list data, schematics, and
component layout diagrams. To obtain FMRs, contact the Customer Care and Services Division (refer to “Appendix A
Replacement Parts Ordering”).

Computer Software Copyrights

The Motorola products described in this manual may include copyrighted Motorola computer programs stored in
semiconductor memories or other media. Laws in the United States and other countries preserve for Motorola certain
exclusive rights for copyrighted computer programs, including, but not limited to, the exclusive right to copy or reproduce in
any form the copyrighted computer program. Accordingly, any copyrighted Motorola computer programs contained in the
Motorola products described in this manual may not be copied, reproduced, modified, reverse-engineered, or distributed in
any manner without the express written permission of Motorola. Furthermore, the purchase of Motorola products shall not
be deemed to grant either directly or by implication, estoppel, or otherwise, any license under the copyrights, patents or
patent applications of Motorola, except for the normal non-exclusive license to use that arises by operation of law in the
sale of a product.

Document Copyrights

No duplication or distribution of this document or any portion thereof shall take place without the express written permission
of Motorola. No part of this manual may be reproduced, distributed, or transmitted in any form or by any means, electronic
or mechanical, for any purpose without the express written permission of Motorola.

Disclaimer

The information in this document is carefully examined, and is believed to be entirely reliable. However, no responsibility is
assumed for inaccuracies. Furthermore, Motorola reserves the right to make changes to any products herein to improve
readability, function, or design. Motorola does not assume any liability arising out of the applications or use of any product
or circuit described herein; nor does it cover any license under its patent rights nor the rights of others.

Trademarks

MOTOROLA, the Stylized M logo, and ASTRO are registered in the US Patent & Trademark Office. All other product or
service names are the property of their respective owners.

© 2007–2008 by Motorola, Inc.

Document History iii

Document History

The following major changes have been implemented in this manual since the previous edition:

Edition Description Date

6871620L01-A Initial edition Mar 2007

6871620L01-B Added UHF info Jan 2008

6871620L01-C Added Parts List for NUE7350B May 2008

6871620L01-C May 28, 2008

iv Table of Contents

Table of Contents

Foreword.........................................................................................................ii

Product Safety and RF Exposure Compliance ............................................................................................ii

Manual Revisions ........................................................................................................................................ii

Computer Software Copyrights....................................................................................................................ii

Document Copyrights ..................................................................................................................................ii

Disclaimer ....................................................................................................................................................ii

Trademarks..................................................................................................................................................ii

Document History .........................................................................................iii

List of Figures ..............................................................................................vii

List of Tables .................................................................................................ix

Commercial Warranty ...................................................................................xi

Limited Warranty.........................................................................................................................................xi

Chapter 1 Introduction ......................................................................... 1-1

1.1 General .......................................................................................................................................... 1-1

1.2 Notations Used in This Manual ...................................................................................................... 1-2

1.3 General Repair Procedures and Techniques.................................................................................1-3

Chapter 2 Radio Power ........................................................................ 2-1

2.1 General .......................................................................................................................................... 2-1

2.2 DC Power Routing–Transceiver Section ....................................................................................... 2-2

2.3 DC Power Routing—VOCON Section ........................................................................................... 2-2

Chapter 3 Theory of Operation............................................................ 3-1

3.1 Transceiver Section ....................................................................................................................... 3-2

3.2 VOCON Section........................................................................................................................... 3-13

3.3 Encryption Module ....................................................................................................................... 3-29

May 28, 2008 6871620L01-C

Table of Contents v

Chapter 4 Troubleshooting Procedures ............................................. 4-1

4.1 Handling Precautions..................................................................................................................... 4-1

4.2 Recommended Service Tools........................................................................................................ 4-2

4.3 Voltage Measurement and Signal Tracing..................................................................................... 4-3

4.4 Standard Bias Table ...................................................................................................................... 4-4

4.5 Power-Up Self-Check Errors ......................................................................................................... 4-5

4.6 Power-Up Self-Check Diagnostics and Repair (Not for Field Use)................................................ 4-6

Chapter 5 Troubleshooting Charts ..................................................... 5-1

5.1 List of Troubleshooting Charts ....................................................................................................... 5-1

5.2 Main Troubleshooting Flowchart.................................................................................................... 5-2

5.3 Power-Up Failure........................................................................................................................... 5-3

5.4 DC Supply Failure.......................................................................................................................... 5-6

5.5 Display Failure ............................................................................................................................. 5-10

5.6 Volume Set Error ......................................................................................................................... 5-13

5.7 Button Test .................................................................................................................................. 5-14

5.8 Top/Side Button Test ................................................................................................................... 5-15

5.9 VCO TX/RX Unlock ..................................................................................................................... 5-16

5.10 VOCON TX Audio........................................................................................................................ 5-17

5.11 VOCON RX Audio ....................................................................................................................... 5-19

5.12 RX RF .......................................................................................................................................... 5-21

5.13 TX RF .......................................................................................................................................... 5-26

5.14 Keyload Failure............................................................................................................................ 5-29

5.15 Secure Hardware Failure............................................................................................................. 5-30

Chapter 6 Troubleshooting Waveforms ............................................. 6-1

6.1 List of Waveforms .......................................................................................................................... 6-1

6.2 24.576 MHz Clock ......................................................................................................................... 6-2

6.3 16.8 MHz Buffer Input and Output ................................................................................................. 6-3

6.4 32.768 kHz Clock Outputs ............................................................................................................. 6-4

6.5 Receive Serial Audio Port (SAP) ................................................................................................... 6-5

6.6 Receive Baseband Interface Port (RX BBP) ................................................................................. 6-6

6.7 Transmit Baseband Interface Port (TX BBP)................................................................................. 6-7

Chapter 7 Troubleshooting Tables ..................................................... 7-1

7.1 List of Board and IC Signals .......................................................................................................... 7-1

Chapter 8 Schematics, Board Overlays, and Parts Lists – VHF....... 8-1

8.1 List of Schematics and Boards Overlays .......................................................................................8-1

8.2 List of Partslist ............................................................................................................................... 8-1

8.3 General Section ............................................................................................................................. 8-2

8.4 Transceiver (RF) Section............................................................................................................... 8-5

8.5 VOCON Section........................................................................................................................... 8-12

8.6 Main Board (NUD7115B ) Parts List............................................................................................8-18

6871620L01-C May 28, 2008

vi Table of Contents

Chapter 9 Schematics, Board Overlays, and Parts Lists – UHF ...... 9-1

9.1 List of Schematics and Boards Overlays .......................................................................................9-1

9.2 List of Partslist................................................................................................................................ 9-1

9.3 General Section ............................................................................................................................. 9-2

9.4 Transceiver (RF) Section ............................................................................................................... 9-5

9.5 VOCON Section........................................................................................................................... 9-13

9.6 Main Board (NUE7350A) Parts List .............................................................................................9-18

9.7 Main Board (NUE7350B) Parts List .............................................................................................9-28

Appendix A Replacement Parts Ordering..............................................A-1

A.1 Basic Ordering Information ............................................................................................................A-1

A.2 Motorola Online..............................................................................................................................A-1

A.3 Mail Orders ....................................................................................................................................A-1

A.4 Telephone Orders ..........................................................................................................................A-1

A.5 Fax Orders .....................................................................................................................................A-2

A.6 Parts Identification .........................................................................................................................A-2

A.7 Product Customer Service .............................................................................................................A-2

Appendix B Motorola Service Centers...................................................B-1

B.1 Servicing Information .....................................................................................................................B-1

B.2 Motorola Service Center ................................................................................................................B-1

B.3 Motorola Federal Technical Center................................................................................................B-1

B.4 Motorola Canadian Technical Logistics Center .............................................................................B-1

Glossary......................................................................................... Glossary-1

Index..................................................................................................... Index-1

May 28, 2008 6871620L01-C

List of Figures vii

List of Figures

Figure 2-1. DC Power Distribution – VHF/ UHF Radio............................................................................ 2-1

Figure 3-1. XTS 4000 Overall Block Diagram ......................................................................................... 3-1

Figure 3-2. RF Transceiver Block Diagram ............................................................................................. 3-2

Figure 3-3. Receiver Block Diagram ....................................................................................................... 3-4

Figure 3-4. Abacus III (AD9864) Functional Block Diagram (from data sheet) ....................................... 3-6

Figure 3-5. Transmitter Block Diagram ................................................................................................... 3-7

Figure 3-6. VOCON Section Connections............................................................................................. 3-13

Figure 3-7. Patriot EIM and Memory Block Diagram............................................................................. 3-18

Figure 3-8. CE Connector ..................................................................................................................... 3-23

Figure 3-9. Control Top Flex.................................................................................................................. 3-25

Figure 3-10. VOCON Transmit Audio Path ............................................................................................. 3-26

Figure 3-11. VOCON Receive Audio Path .............................................................................................. 3-27

Figure 3-12. Radio ON/OFF Circuitry...................................................................................................... 3-28

Figure 6-1. 24.576 MHz Clock Waveform ............................................................................................... 6-2

Figure 6-2. 16.8 MHz Buffer Input and Output Waveforms ..................................................................... 6-3

Figure 6-3. 32.768 kHz Clock Outputs Waveforms ................................................................................. 6-4

Figure 6-4. Receive Serial Audio Port (SAP) Waveforms ....................................................................... 6-5

Figure 6-5. Receive Baseband Interface Port (RX BBP) Waveforms ..................................................... 6-6

Figure 6-6. Transmit Baseband Interface Port (TX BBP) Waveforms ..................................................... 6-7

Figure 8-1. Main Board Layout (NUD7115B) – Side 1 ............................................................................ 8-2

Figure 8-2. Main Board Layout (NUD7115B) – Side 2 ............................................................................ 8-3

Figure 8-3. VHF Main Board Overall Schematic .....................................................................................8-4

Figure 8-4. VHF Transceiver (RF) Board Overall Circuit Schematic....................................................... 8-5

Figure 8-5. VHF Transceiver (RF) Antenna Switch and Harmonic Filter Circuits ................................... 8-6

Figure 8-6. VHF Transceiver (RF) Receiver Front End Circuit................................................................ 8-7

Figure 8-7. VHF Transceiver (RF) Receiver Back End Circuit ................................................................ 8-8

Figure 8-8. VHF Transceiver (RF) Transmitter Circuit ............................................................................ 8-9

Figure 8-9. VHF Frequency Generation Unit (Synthesizer) Circuit – 1 of 2 .......................................... 8-10

Figure 8-10. VHF Frequency Generation Unit (VCO) Circuit – 2 of 2 ..................................................... 8-11

Figure 8-11. VOCON: Overall Circuit Schematic ....................................................................................8-12

Figure 8-12. VOCON: Audio, Connector Interface Circuits ..................................................................... 8-13

Figure 8-13. VOCON: Controller and Memory Circuits ........................................................................... 8-14

Figure 8-14. VOCON: DC Power, Clocks and ON/OFF Circuit............................................................... 8-15

Figure 8-15. VOCON: Audio and Accessory Interface Circuits............................................................... 8-16

Figure 8-16. VOCON: Miscellaneous Circuits ......................................................................................... 8-17

Figure 9-1. Main Board Layout (NUE7350A/B) – Side 1......................................................................... 9-2

Figure 9-2. Main Board Layout (NUE7350A/B) – Side 2......................................................................... 9-3

Figure 9-3. UHF Main Board Overall Schematic .....................................................................................9-4

Figure 9-4. UHF Transceiver (RF) Board Overall Circuit Schematic....................................................... 9-5

Figure 9-5. UHF Transceiver (RF) Antenna Switch and Harmonic Filter Circuits ................................... 9-6

Figure 9-6. UHF Transceiver (RF) Receiver Front End Circuit ............................................................... 9-7

Figure 9-7. UHF Transceiver (RF) Receiver Back End Circuit................................................................ 9-8

Figure 9-8. UHF Transceiver (RF) Transmitter Circuit ............................................................................ 9-9

Figure 9-9. UHF Frequency Generation Unit (Synthesizer) Circuit – 1 of 3 .......................................... 9-10

Figure 9-10. UHF Frequency Generation Unit (TX VCO) Circuit – 2 of 3 ............................................... 9-11

Figure 9-11. UHF Frequency Generation Unit (RX VCO) Circuit – 3 of 3 ............................................... 9-12

Figure 9-12. VOCON: Overall Circuit Schematic ....................................................................................9-13

Figure 9-13. VOCON: Audio, Connector Interface Circuits ..................................................................... 9-14

6871620L01-C May 28, 2008

viii List of Figures

Figure 9-14. VOCON: Controller and Memory Circuits ........................................................................... 9-15

Figure 9-15. VOCON: DC Power, Clocks and ON/OFF Circuit ............................................................... 9-16

Figure 9-16. VOCON: Audio and Accessory Interface Circuits ............................................................... 9-17

May 28, 2008 6871620L01-C

List of Tables ix

List of Tables

Table 1-1. Lead Free Solder Wire Part Number List.............................................................................. 1-3

Table 1-2. Lead Free Solder Paste Part Number List............................................................................ 1-3

Table 2-1. Conventional Batteries.......................................................................................................... 2-1

Table 2-2. Transceiver Voltage Regulators............................................................................................ 2-2

Table 2-3. VOCON Section DC Power Distribution ............................................................................... 2-3

Table 3-1. Battery Connector M1705..................................................................................................... 3-2

Table 3-2. Transceiver – VOCON Interface Signals .............................................................................. 3-3

Table 3-3. Power Control IC (U104) Pin Descriptions............................................................................ 3-9

Table 3-4. Option-Select Functions ..................................................................................................... 3-23

Table 3-5. ON/OFF Operation Truth Table........................................................................................... 3-29

Table 3-6. Encryption Module Software Kits and Algorithms............................................................... 3-29

Table 4-1. Recommended Service Tools ............................................................................................... 4-2

Table 4-2. Standard Operating Bias....................................................................................................... 4-4

Table 4-3. Power-Up Self-Check Error Codes.......................................................................................4-5

Table 4-4. Power-Up Self-Check Diagnostic Actions............................................................................. 4-6

Table 5-1. Troubleshooting Charts List .................................................................................................. 5-1

Table 6-1. List of Waveforms ................................................................................................................. 6-1

Table 7-1. List of Tables of Board and IC Signals.................................................................................. 7-1

Table 7-2. J1 Mainboard to Keypad Flex and Display Module............................................................... 7-2

Table 7-3. J2 Mainboard to UCM, CE and Audio Jack Board................................................................ 7-4

Table 7-4. J3 Mainboard to Top and Side Control Flex.......................................................................... 7-5

Table 7-5. U1410 FLASH Pinouts.......................................................................................................... 7-6

Table 7-6. U1409 SRAM Pinouts ........................................................................................................... 7-8

Table 7-7. U1401 Patriot MCU/DSP IC Pinouts................................................................................... 7-10

Table 7-8. U1304 MAKO Pinouts......................................................................................................... 7-19

Table 8-1. List of Mainboard Schematics and Board Overlays .............................................................. 8-1

Table 8-2. List of Partslist....................................................................................................................... 8-1

Table 9-1. List of Mainboard Schematics and Board Overlays .............................................................. 9-1

Table 9-2. List of Partslist....................................................................................................................... 9-1

6871620L01-C May 28, 2008

x List of Tables

Related Publications

XTS 4000 Digital Portable Radio User Guide.............................................................................6871618L01

XTS 4000 Digital Portable Radios Basic Service Manual ..........................................................6871619L01

XTS 4000 Digital Portable Radio User Guide (CD) ....................................................................PMLN5057_

Chassis Eliminator Leaflet .........................................................................................................6871568M01

May 28, 2008 6871620L01-C

Commercial Warranty xi

Commercial Warranty

Limited Warranty

MOTOROLA COMMUNICATION PRODUCTS

I. What This Warranty Covers And For How Long

MOTOROLA INC. (“MOTOROLA”) warrants the MOTOROLA manufactured Communication
Products listed below (“Product”) against defects in material and workmanship under normal use and
service for a period of time from the date of purchase as scheduled below:

ASTRO XTS 4000 Digital Portable Units One (1) Year

Product Accessories One (1) Year

Motorola, at its option, will at no charge either repair the Product (with new or reconditioned parts),
replace it (with a new or reconditioned Product), or refund the purchase price of the Product during
the warranty period provided it is returned in accordance with the terms of this warranty. Replaced
parts or boards are warranted for the balance of the original applicable warranty period. All replaced
parts of Product shall become the property of MOTOROLA.

This express limited warranty is extended by MOTOROLA to the original end user purchaser only
and is not assignable or transferable to any other party. This is the complete warranty for the Product
manufactured by MOTOROLA. MOTOROLA assumes no obligations or liability for additions or
modifications to this warranty unless made in writing and signed by an officer of MOTOROLA.
Unless made in a separate agreement between MOTOROLA and the original end user purchaser,
MOTOROLA does not warrant the installation, maintenance or service of the Product.

MOTOROLA cannot be responsible in any way for any ancillary equipment not furnished by
MOTOROLA which is attached to or used in connection with the Product, or for operation of the
Product with any ancillary equipment, and all such equipment is expressly excluded from this
warranty. Because each system which may use the Product is unique, MOTOROLA disclaims
liability for range, coverage, or operation of the system as a whole under this warranty.

II. General Provisions

This warranty sets forth the full extent of MOTOROLA’s responsibilities regarding the Product.
Repair, replacement or refund of the purchase price, at MOTOROLA’s option, is the exclusive
remedy. THIS WARRANTY IS GIVEN IN LIEU OF ALL OTHER EXPRESS WARRANTIES. IMPLIED
WARRANTIES, INCLUDING WITHOUT LIMITATION, IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED TO THE
DURATION OF THIS LIMITED WARRANTY. IN NO EVENT SHALL MOTOROLA BE LIABLE FOR
DAMAGES IN EXCESS OF THE PURCHASE PRICE OF THE PRODUCT, FOR ANY LOSS OF
USE, LOSS OF TIME, INCONVENIENCE, COMMERCIAL LOSS, LOST PROFITS OR SAVINGS
OR OTHER INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
USE OR INABILITY TO USE SUCH PRODUCT, TO THE FULL EXTENT SUCH MAY BE
DISCLAIMED BY LAW.

6871620L01-C May 28, 2008

xii Commercial Warranty

III. State Law Rights

SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR
CONSEQUENTIAL DAMAGES OR LIMITATION ON HOW LONG AN IMPLIED WARRANTY
LASTS, SO THE ABOVE LIMITATION OR EXCLUSIONS MAY NOT APPLY.

This warranty gives specific legal rights, and there may be other rights which may vary from state to
state.

IV. How To Get Warranty Service

You must provide proof of purchase (bearing the date of purchase and Product item serial number)
in order to receive warranty service and, also, deliver or send the Product item, transportation and
insurance prepaid, to an authorized warranty service location. Warranty service will be provided by
Motorola through one of its authorized warranty service locations. If you first contact the company
which sold you the Product, it can facilitate your obtaining warranty service. You can also call
Motorola at 1-888-567-7347 US/Canada.

V. What This Warranty Does Not Cover

A. Defects or damage resulting from use of the Product in other than its normal and customary

manner.

B. Defects or damage from misuse, accident, water, or neglect.

C. Defects or damage from improper testing, operation, maintenance, installation, alteration,

modification, or adjustment.

D. Breakage or damage to antennas unless caused directly by defects in material workmanship.

E. A Product subjected to unauthorized Product modifications, disassemblies or repairs

(including, without limitation, the addition to the Product of non-Motorola supplied equipment)
which adversely affect performance of the Product or interfere with Motorola's normal
warranty inspection and testing of the Product to verify any warranty claim.

F. Product which has had the serial number removed or made illegible.

G. Rechargeable batteries if:

• any of the seals on the battery enclosure of cells are broken or show evidence of
tampering.

• the damage or defect is caused by charging or using the battery in equipment or service
other than the Product for which it is specified.

H. Freight costs to the repair depot.

I. A Product which, due to illegal or unauthorized alteration of the software/firmware in the

Product, does not function in accordance with MOTOROLA’s published specifications or the
FCC type acceptance labeling in effect for the Product at the time the Product was initially
distributed from MOTOROLA.

J. Scratches or other cosmetic damage to Product surfaces that does not affect the operation of

the Product.

K. Normal and customary wear and tear.

May 28, 2008 6871620L01-C

Commercial Warranty xiii

VI. Patent And Software Provisions

MOTOROLA will defend, at its own expense, any suit brought against the end user purchaser to the
extent that it is based on a claim that the Product or parts infringe a United States patent, and
MOTOROLA will pay those costs and damages finally awarded against the end user purchaser in
any such suit which are attributable to any such claim, but such defense and payments are
conditioned on the following:

A. that MOTOROLA will be notified promptly in writing by such purchaser of any notice of such

claim;

B. that MOTOROLA will have sole control of the defense of such suit and all negotiations for its

settlement or compromise; and

C. should the Product or parts become, or in MOTOROLA’s opinion be likely to become, the

subject of a claim of infringement of a United States patent, that such purchaser will permit
MOTOROLA, at its option and expense, either to procure for such purchaser the right to
continue using the Product or parts or to replace or modify the same so that it becomes
noninfringing or to grant such purchaser a credit for the Product or parts as depreciated and
accept its return. The depreciation will be an equal amount per year over the lifetime of the
Product or parts as established by MOTOROLA.

MOTOROLA will have no liability with respect to any claim of patent infringement which is based
upon the combination of the Product or parts furnished hereunder with software, apparatus or
devices not furnished by MOTOROLA, nor will MOTOROLA have any liability for the use of ancillary
equipment or software not furnished by MOTOROLA which is attached to or used in connection with
the Product. The foregoing states the entire liability of MOTOROLA with respect to infringement of
patents by the Product or any parts thereof.

Laws in the United States and other countries preserve for MOTOROLA certain exclusive rights for
copyrighted MOTOROLA software such as the exclusive rights to reproduce in copies and distribute
copies of such Motorola software. MOTOROLA software may be used in only the Product in which
the software was originally embodied and such software in such Product may not be replaced,
copied, distributed, modified in any way, or used to produce any derivative thereof. No other use
including, without limitation, alteration, modification, reproduction, distribution, or reverse
engineering of such MOTOROLA software or exercise of rights in such MOTOROLA software is
permitted. No license is granted by implication, estoppel or otherwise under MOTOROLA patent
rights or copyrights.

VII. Governing Law

This Warranty is governed by the laws of the State of Illinois, USA.

6871620L01-C May 28, 2008

xiv Commercial Warranty

Notes

May 28, 2008 6871620L01-C

Introduction: General 1-1

Chapter 1 Introduction

1.1 General

This manual includes all the information needed to maintain peak product performance and
maximum working time for the ASTRO XTS 4000 radio. This detailed level of service (component
level) is typical of the service performed by some service centers, self-maintained customers, and
distributors.

Use this manual in conjunction with the ASTRO XTS 4000 Digital Portable Radios Basic Service
Manual (Motorola part number 6871619L01), which can help in troubleshooting a problem to a
particular printed circuit (PC) board.

Conduct the basic performance checks outlined in the basic service manual first to verify the need to
analyze the radio and to help pinpoint the functional problem area. In addition, you will become
familiar with the radio test mode of operation, which is a helpful tool. If any basic receive or transmit
parameters fail to be met, the radio should be aligned according to the radio alignment procedure.

Included in other areas of this manual are functional block diagrams, detailed theory of operation,
troubleshooting charts and waveforms, schematics, and parts lists. You should become familiar with
these sections to aid in determining circuit problems. Also included are component location diagrams
to aid in locating individual circuit components and some IC diagrams, which identify some
convenient probe points.

“Chapter 3, Theory of Operation,” on page 3-1, contains detailed descriptions of the operations of

many circuits. Once you locate the problem area, review the troubleshooting flowchart for that circuit
to fix the problem.

6871620L01-C May 28, 2008

1-2 Introduction: Notations Used in This Manual

1.2 Notations Used in This Manual

Throughout the text in this publication, you will notice the use of warnings, cautions, and notes.
These notations are used to emphasize that safety hazards exist, and care must be taken and
observed.

NOTE: An operational procedure, practice, or condition that is essential to emphasize.

!

C a u t i o n

!

!

W A R N I N G

!

D A N G E R

CAUTION indicates a potentially hazardous situation which, if
not avoided, might

WARNING indicates a potentially hazardous situation
which, if not avoided, could

DANGER indicates an imminently hazardous
situation which, if not avoided, will
injury.

result in equipment damage.

result in death or injury.

result in death or

May 28, 2008 6871620L01-C

Introduction: General Repair Procedures and Techniques 1-3

1.3 General Repair Procedures and Techniques

NOTE

Environmentally Preferred Products (EPP) (refer to the marking on the printed circuit
boards — examples shown below) were developed and assembled using environmen­tally preferred components and solder assembly techniques to comply with the Euro­pean Union’s Restriction of Hazardous Substances (ROHS) Directive 2002/95/EC
and Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC. To
maintain product compliance and reliability, use only the Motorola specified parts in this
manual.

Any rework or repair on Environmentally Preferred Products must be done using the appropriate
lead-free solder wire and lead-free solder paste as stated in the following table:

Table 1-1. Lead Free Solder Wire Part Number List

Motorola

Part Number

1088929Y01 95.5Sn/3.8Ag/0.7Cu RMA Version 2.7-3.2% 217C 52171 0.015” 1lb spool

Alloy Flux Type

Flux Content

by Weight

Melting

Point

Supplier Part

number

Diameter Weight

Table 1-2. Lead Free Solder Paste Part Number List

Motorola Part

Number

1085674C03 NC-SMQ230 900-1000KCPs

Manufacturer Part

Number

Parts Replacement and Substitution

When damaged parts are replaced, identical parts should be used. If the identical replacement
component is not locally available, check the parts list for the proper Motorola part number and order
the component from the nearest Motorola Radio Products and Solutions Organization listed in

Appendix A of this manual.

1.3.1 Rigid Circuit Boards

The family of radios uses bonded, multi-layer, printed circuit boards. Since the inner layers are not
accessible, some special considerations are required when soldering and unsoldering components.
The through-plated holes may interconnect multiple layers of the printed circuit. Therefore, care
should be exercised to avoid pulling the plated circuit out of the hole.

When soldering near the connector pins:

• avoid accidentally getting solder in the connector.

• be careful not to form solder bridges between the connector pins

• closely examine your work for shorts due to solder bridges.

Viscosity Type Composition & Percent Metal

Brookfield (5rpm)

Typ e 3

(-325/+500)

(95.5%Sn-3.8%Ag-0.7%Cu)

89.3%

Liquid

Temperature

217°C

6871620L01-C May 28, 2008

1-4 Introduction: General Repair Procedures and Techniques

1.3.2 Chip Components

Use the RLN4062 Hot-Air Repair Station for chip component replacement. Adjust the temperature
control to 390 °C (735 °F), and adjust the airflow to a minimum setting. Airflow can vary due to
component density.

• To remove a chip component:

1. Use a hot-air hand piece and position the nozzle of the hand piece approximately 0.3 cm

(1/8”) above the component to be removed.

2. Begin applying the hot air. Once the solder reflows, remove the component using a pair

of tweezers.

3. Using a solder wick and a soldering iron or a power desoldering station, remove the

excess solder from the pads.

• To replace a chip component using a soldering iron:

1. Select the appropriate micro-tipped soldering iron and apply fresh solder to one of the

solder pads.

2. Using a pair of tweezers, position the new chip component in place while heating the

fresh solder.

3. Once solder wicks onto the new component, remove the heat from the solder.

4. Heat the remaining pad with the soldering iron and apply solder until it wicks to the

component. If necessary, touch up the first side. All solder joints should be smooth and
shiny.

• To replace a chip component using hot air:

1. Use the hot-air hand piece and reflow the solder on the solder pads to smooth it.

2. Apply a drop of solder paste flux to each pad.

3. Using a pair of tweezers, position the new component in place.

4. Position the hot-air hand piece approximately 0.3 cm (1/8” ) above the component and

begin applying heat.

5. Once the solder wicks to the component, remove the heat and inspect the repair. All

joints should be smooth and shiny.

NOTE

Parts U1401 and U1304 are not field repairable. For failures relating to U1401 and
U1304, the mainboard has to be replaced.

May 28, 2008 6871620L01-C

Introduction: General Repair Procedures and Techniques 1-5

1.3.3 Shields

Removing and replacing shields is recommended to be done with the Air Blower,
BOSCH GHG 600-3 or equivalent.

• To remove the shield:

1. Place the circuit board in the circuit board holder.

2. Add solder paste flux around the base of the shield.

3. Position the heat-focus head onto the shield.

4. Turn on the heater and wait until the shield lifts off the circuit board.

5. Once the shield is off, turn off the heat, and grab the part with a pair of tweezers.

6. Remove the circuit board from the circuit board holder.

• To replace the shield:

1. Add solder to the shield if necessary, using a micro-tipped soldering iron.

2. Next, rub the soldering iron tip along the edge of the shield to smooth out any excess

solder. Use solder wick and a soldering iron to remove excess solder from the solder
pads on the circuit board.

3. Place the circuit board back in the circuit board holder.

4. Place the shield on the circuit board using a pair of tweezers.

5. Position the heat-focus head over the shield.

6. Turn on the heater and wait for the solder to reflow.

7. Once complete, turn off the heat, raise the heat-focus head and wait approximately one

minute for the part to cool.

8. Remove the circuit board and inspect the repair. No cleaning should be necessary.

6871620L01-C May 28, 2008

1-6 Introduction

Notes

May 28, 2008 6871620L01-C

Radio Power: General 2-1

Chapter 2 Radio Power

This chapter provides a detailed circuit description of the power distribution of an ASTRO XTS 4000
radio.

2.1 General

In the ASTRO XTS 4000 radio, power (B+) is distributed to two sections: the transceiver (RF) section
and the VOCON section (see Figure 2-1.)

Power for the radio is provided through a battery supplying a nominal 7.5 Vdc directly to the
mainboard. The following battery types and capacities are available:

Table 2-1. Conventional Batteries

Part Number Description

NNTN6944 630mAH Li-Ion Battery

BATTERY

UNSW_B+

VCC5

5 Volts

Digital

Circuits

5V_MISC

FET

3.8V(VSW1)

2.9 Volts
Digital

Circuits

SW_B+

V2

MAKO

1.55

Volts

Patriot

5 Volts

1.875
Volts

Patriot

7.5 Volts
(Nominal)

BATT

RAW B+

(to XCVR)

SW_B+_

(control signal)

3 Volts

RF Circuits

Fuse

XB+ FB+

V5A

5 Volts

V5R

5 Volts

Analog Circuits

V3DV3A

3 Volts

RF Circuits

FET

Figure 2-1. DC Power Distribution – VHF/ UHF Radio

B+ from the battery is electrically switched to most of the radio. The electrical switching of B+
supports a keep-alive mode. Under software control, even when the radio is turned off, power
remains on until the MCU completes its power-down, at which time the radio is physically powered
down.

6871620L01-C May 28, 2008

2-2 Radio Power: DC Power Routing–Transceiver Section

2.2 DC Power Routing–Transceiver Section

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

schematics showing the transceiver board DC power routing components.

Contact M1705, the B-plus assembly, connects the battery to the mainboard. Capacitors C20 and
C24 provide protection against momentary breaks at the B-plus connector due to contact bounce
when the radio is dropped.

VHF/ UHF: Components C4, C6 and E101 forms a power-line filter for signal RAWB+, which
supplies battery voltage to the transmitter PA.

Transistor Q1301, controlled by signal FET_ENX from the MAKO IC, turns on XSWB+2, which
supplies to the 5-V linear regulator, U1 and TX_ALC block.

Fuse F901 and filter E1104, C1128 and C1129 supply fused B-plus to the VOCON section. In turn,
the VOCON section supplies VSW1, regulated 3.8 Vdc, from the MAKO (Audio, Power & Accessory
Interface IC) switching regulator to the XCVR. VSW1 supplies to the 3V linear regulators in the
transceiver section. The XCVR regulated power supplies are summarized in Table 2-2.

Table 2-2. Transceiver Voltage Regulators

Ref.

Desig.

U1 LP2989 V5A Regulated 5.0 Vdc

U2 LP3985 V3D Regulated 3.0 Vdc digital

U3 LP3985 V3A Regulated 3.0 Vdc analog for synthesizer

IC

Name

Output

Signal Name

Description

2.3 DC Power Routing—VOCON Section

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

schematics showing the VOCON section DC power routing components.

UNSW_B+, or unswitched B+, is routed to Q1301, Q1302 and the MAKO on the VOCON section.

The ON/OFF circuitry block is made up of Q9906, U9901, U9902, U9918, U9903 and Q9904. The
ON_OFF signal triggers the ON/OFF circuitry block which pulls the MECH_SW pin of the MAKO low,
enabling the routing of SWB+ to the XCVR and VOCON sections and the encryption module. SW B+
and UNSW B+ are also supplied to the encryption module through connector J701.

Transistor Q9906 is also under the control of the microcontroller unit (MCU) via V2_FIL from MAKO.
This allows the MCU detect the pressing of the ON/OFF button and to follow an orderly power-down
sequence when it senses that SWB+ is off. This sense is provided through MECH_SW.

May 28, 2008 6871620L01-C

Radio Power: DC Power Routing—VOCON Section 2-3

The digital circuits in the VOCON section are powered from regulators located in the MAKO IC
(U1304). The MAKO IC provides five supplies: VSW1, V2, V1.55, V1.875 and VCC5. These
regulators are software programmable except for VCC5. Table 2-3 lists the supply voltages and the
circuits that use these voltages.

Table 2-3. VOCON Section DC Power Distribution

Supply

Name

UNSW_B+ 9 to 6 Vdc

SW_B+ 9 to 6 Vdc

VCC5 5Vdc Linear

VSW1 3.8 Vdc Switching

V1.875 1.875 Vdc Switching

V2 2.9 Vdc Linear

Output

Voltag e

7.5 Vdc
nominal

7.5 Vdc
nominal

Supply Type

Battery N/A MAKO IC

Battery N/A MAKO

Regulator

regulator
software
progammable

regulator
software
progammable

regulator
software
programmable

Unprogrammed
Output Voltage

N/A MAKO Int. / ext. microphone

3.2 Vdc 3-V regulators (XCVR)

1.9 Vdc Patriot core

2.775 Vdc Patriot I/O ring

Circuits Supplied

5V Misc. Regulator

XCVR 5V Regulator
CE Interface
Encryption Module

bias
MAKO Audio preamplifier

VSW2 input
V2 input

FLASH IC
SRAM
Display module

Display module

16.8 MHz buffer

V1.55 1.55 Vdc Linear

regulator

6871620L01-C May 28, 2008

N/A Patriot core

2-4 Radio Power

Notes

May 28, 2008 6871620L01-C

Theory of Operation: General 3-1

Chapter 3 Theory of Operation

This chapter provides a detailed circuit description of the ASTRO XTS 4000 mainboard (contains RF
transceiver and VOCON sections). When reading the theory of operation, refer to the appropriate
schematic and component location diagrams located in the back of this manual. This detailed theory
of operation can help isolate the problem to a particular component.

The ASTRO XTS 4000 digital portable radio is a microcontroller-based transceiver incorporating a
digital signal processor (DSP). The microcontroller handles the general radio control, monitors
status, and processes commands input from the keypad or other user controls. The DSP processes
the typical analog signals, and generates the standard signaling digitally to provide compatibility with
existing analog systems. In addition, the DSP provides digital modulation techniques, utilizing voice
encoding techniques with error correction schemes. This provides the user with enhanced range and
audio quality, all in a reduced bandwidth channel requirement. It allows embedded signaling, which
can mix system information and data with digital voice to support a multitude of system features.

The ASTRO XTS 4000 radio (see Figure 3-1) consists of the following:

• Band-dependent mainboard (contains RF Transceiver and VOCON sections)

• Front Flip Assembly (containing Display, Keypad and Encryption Module)

• Radio Chassis Assembly (containing Audio Jack, CE Interface Connector and Controls)

Front Flip

Front Flip

Assembly

Assembly

Earpiece

Earpiece

Main & CID

Main & CID

Display

Display

Keypad

Keypad

Encryption Module

Encryption Module

Speaker,

Speaker,

Microphone, Haptic

Microphone, Haptic

Device

Device

Battery

Battery

3

3

M1705

M1705

TRANSCEIVER

TRANSCEIVER

Section

Section

MAINBOARD

MAINBOARD

J1

J1

60

60

Figure 3-1. XTS 4000 Overall Block Diagram

VOCON

VOCON

Section

Section

RF

RF

J2

J2

Antenna

Antenna

M1704

M1704

30

30

J3

J3

1

1

16

16

Radio

Radio

Chassis

Chassis

Assembly

Assembly

Controls

Controls

CE Interface
CE Interface
Connector

Audio Jack

Audio Jack

6871620L01-C May 28, 2008

3-2 Theory of Operation: Transceiver Section

3.1 Transceiver Section

The transceiver (XCVR) section performs the transmitter and receiver functions necessary to
translate between voice and data from the VOCON section and the modulated radio-frequency (RF)
carrier at the antenna. The transceiver section contains all the radio’s RF circuits for the following
major components:

• Receiver

• Transmitter

• Frequency Generation Unit (FGU)

Figure 3-2 illustrates the transceiver board block diagram.

Thermistor

Thermistor

U103

U103

PCIC

PCIC
U104

U104

Power Amp

Q107

Step

Attenuator

U701

Pre-

Selector

Filter

Current

Current

Sense

Sense

2ndThermal

2ndThermal

Cutback

Cutback

Tx Driver

U102

-

RX LNA

Q430

Post-

Selector

Filter

-

VCO Buffer
U302 (VHF)

Mixer
U470

Tx VCO

Rx VCO

Rx VCO

Crystal Filt er

FL490

FGU

Loop
Filter

FractN
U202

ABACUS III

ABACUS III

U500

U500

2ndLO

LPF

DAC

FL200

U203

A-D

A-D

Referenc e
Oscillator Y2 00

Sample

Clk

3

3

3

Tx SSI
from
VOCON
Section

Rx SSI
to
VOCON
Section

To Antenna

Matching

-

50-Ohm

Antenna

Network

RF Jack
J1704

Harmonic

Filter

Antenna

Switch

Tx

Tx

Rx

Figure 3-2. RF Transceiver Block Diagram

3.1.1 Connections

This section describes the various connections to and from the transceiver section.

3.1.1.1 Battery Connector M1705

Battery connector M1705 consists of three gold-plated contacts on the printed circuit board that mate
with the battery. Signal descriptions are in Table 3-1.

Table 3-1. Battery Connector M1705

Pin No. Signal Description

1 POS Battery positive terminal, nominally 7.5 Vdc

2 DATA Battery status, from battery to VOCON section

3 NEG Battery negative terminal, tied to PCB GROUND

May 28, 2008 6871620L01-C

Theory of Operation: Transceiver Section 3-3

3.1.1.2 Transceiver and VOCON Section Interface

The transceiver and VOCON section interface is a digital interface carrying DC power, control, and
data between the XCVR and VOCON sections.

Table 3-2 lists the interface connections, their signals, and functions. SPI refers to serial peripheral

interface, which is the control bus from the microprocessor. SSI is the serial synchronous interface
bus for data to and from the DSP. There is a RX SSI bus for demodulated data from the receiver and
a TX SSI bus for modulation data to the transmitter.

Table 3-2. Transceiver – VOCON Interface Signals

VOCON Signal

XRFUNSWB+1 FUB+ O dc Fused B+ to VOCON

XLOCK LOCK O status FGU lock detect

XTX_DATA TXTD O ssi TX SSI data

XSSI_CLK RXCK O ssi RX SSI clock

XSSI_FSYNC RXFS O ssi RX SSI frame sync

X16.8MHz F168 O RF 16.8 MHz reference clock

XSWB+2 XCVR_SWB+ I dc Switch control

XTX_SSFS TXFS I ssi TX SSI frame sync

XTS_SSCK TXCK I ssi TX SSI clock

XRX_DATA RXDO O ssi RX SSI data

XABACUS3_CS ABCS I ssi SPI Abacus chip select

XCVR
Signal

XCVR

I/O

Type Description

XRF_VSW1 VSW1 I dc Regulated 3.8 V

XRF_SCKA SPCK I spi SPI clock

XRF_BAT_STAT DATA O dc Battery status

XRF_MOSIA MOSI I/O spi SPI data I/O

XFN_PC_SEL USEL I spi SPI universal chip select

XRF_POR RSTL I/O control asynchronous reset, active low

3.1.1.3 Antenna Contact M1704

Antenna contact M1704 is a surface mount, leaf spring contact which comes into contact with the
antenna pin on the radio chassis assembly. This contact routes the RF power to/from the transceiver
to the antenna.

6871620L01-C May 28, 2008

3-4 Theory of Operation: Transceiver Section

3.1.1.4 Power Conditioning Components

DC power-conditioning components include zener diodes, capacitors, ferrite beads, a power
inductor, and the fuse. Diode VR3 provides over-voltage protection. Ferrite beads (designated
E1104, etc.) and capacitors suppress electromagnetic interference from the transceiver. The
power-line filter consisting of C4, C6, C20 and C24, suppresses digital noise from the VOCON
section switching power supplies that could degrade the transmitter spectral purity.

Pass transistor Q1301 switches the battery voltage to the transceiver when control signal SWB+ or
XSWB+2 from the VOCON section is asserted high. This increases the transceiver’s immunity to
conducted interference that might be present on SWB+ or XSWB+2, such as from switching voltage
regulators on the VOCON section.

The gold plated perimeter of the PC Board surfaces are critical to the GROUNDing of the radio
system. The front flip assembly and radio chassis assembly sandwiches the PC Board to create a
clam-like shielding design for the radio. The arrangement creates a good GROUNDing connection
for the entire radio assembly. The radio GROUNDing is a necessary electrical reference point to
complete the antenna circuit path. Shields SH01 through SH11 appear on the schematic to show
their connection to GROUND.

3.1.2 Receiver

The XTS 4000 transceiver has a dual-conversion superheterodyne receiver. Figure 3-3 illustrates
the major receiver components:

• Receiver Front End

• Receiver Back End

RF Input

Harmonic

Filter

XTAL

Filter

RX Front End

Antenna

Switch

LO

Tuneable

Pre-Selector

Filter

ABACUS III - RX Back End

LNA

CKO

Tuneable

Post-Selector

Filter

Figure 3-3. Receiver Block Diagram

ADC

1st LO

1st

Mixer

3

to VOCON Section

MAEPF-27278-B

RX_SSI_ DATA

3.1.2.1 Receiver Front End

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

receiver front end schematics.

The receiver front end tunes to the desired channel and down converts the RF signal to the first
intermediate frequency (IF). Channel selection is by way of a tunable local oscillator, RXLO, from the
FGU.

May 28, 2008 6871620L01-C

Theory of Operation: Transceiver Section 3-5

The receiver front end consists of a pre-selector filter, an RF amplifier, a post-selector filter, mixer,
and an IF crystal filter. A switchable attenuator is also inserted between the antenna switch and the
pre-selector filter. The RF amplifier is a discrete RF transistor with associated circuitry. The mixer is a
double-balanced, active mixer IC, coupled by transformers. The receiver (RX) local oscillator (LO) is
provided by the FGU.

3.1.2.1.1 Pre-Selector and Post-Selector Filters

VHF/ UHF: The receiver front end uses two discrete, tunable, bandpass filters to achieve its required
out-of-band rejection. The pre-selector filter precedes the RF amplifier, while the post-selector filter
follows the RF amplifier. DAC2, from the PCIC, is used to simultaneously tune both the pre-selector
and post-selector filters by applying voltage to the varactors.

3.1.2.1.2 LNA (Low-Noise Amplifier)

The XTS 4000 radio uses a discrete transistor for the low-noise amplifier Q430. A feedback network
between the collector and base improves stability and gain balance across the frequency band. Input
and output LC networks match the LNA impedance to 50 ohms.

A diode limiter D703 protects the amplifier damage by strong input signals.

3.1.2.1.3 Mixer

The mixer U470 down-converts the received RF to the first intermediate frequency (IF). The I
F is 44.85 MHz (VHF) and 73.35 MHz (UHF). High-side LO injection is used for the VHF whereas
low-side LO injection is used for the UHF. Transformers are used as baluns to convert signals from
single-ended to balanced at pins RFN and RFP. An output transformer converts the balanced signal
at pins IFN and IFP to a single-ended output.

3.1.2.1.4 IF Filter (Crystal Filter)

The IF filter FL490 is a leadless, surface-mount, 3-pole, quartz crystal filter. This narrow bandpass
filter gives the radio its adjacent-channel and alternate-channel rejection performance.

An input LC network matches the filter impedance to 50 ohms. The output match for the filter
matches the IF Filter output port to the ABACUS III input.

3.1.2.2 Receiver Back End

The receiver back end, which consists of the Abacus III (AD9864 IF digitizing subsystem) IC and its
associated circuitry, processes the down-converted IF signal to produce digital data for final
processing by the VOCON DSP.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

receiver back end schematics.

3.1.2.2.1 Abacus III IC U500

The AD9864 (see Figure 3-4 on page 3-6) is a general-purpose, IF subsystem that digitizes a
low-level 10–300 MHz IF input with a bandwidth up to 270 kHz. The output of the Abacus III IC is SSI
data to the VOCON.

The signal chain of the AD9864 consists of a low-noise amplifier, a mixer, a bandpass sigma-delta
A/D converter, and a decimation filter with programmable decimation factor. An automatic gain
control (AGC) circuit provides the AD9864 with 12 dB of continuous gain adjustment. The high
dynamic range and inherent anti-aliasing provided by the bandpass sigma-delta converter allow the
AD9864 to cope with blocking signals 80 dB stronger than the desired signal.

6871620L01-C May 28, 2008

3-6 Theory of Operation: Transceiver Section

Auxiliary blocks include frequency synthesizers for the second LO and sampling clock LO, as well as
an SPI port. The second LO uses a discrete external loop filter and VCO. The clock oscillator has an
external loop filter and resonator.

MXON

IF2P

MXOP

IF2N

GCP

GCN

IFIN

FREF

AD9864

-16dB

LNA

LO

Synth.

IOUTL

LO VCO and

Loop Filter

LOP

LON

M

ADC

Samp. Clock

Synthesizer

CLKP

IOUTC

CLK VCO and

Loop Filter

DAC AGC

......=13-26MHz

CLKN

Decimation

Filter

Voltage/

Current

Reference

RREF

VREFP

VREFN

Formatting/SSI

Control Logic

SPI

PC

PD

DOUTA

DOUTB

FS

CLKOUT

PE

SYNCB

MAEPF-27412a-O

Figure 3-4. Abacus III (AD9864) Functional Block Diagram (from data sheet)

Input signal RXIF is the 44.85 MHz (VHF) and 73.35 MHz (UHF) IF from crystal filter FL490 in the
receiver front end.

VHF: Components L491 and C491 match the input impedance of the ABACUS III to the IF Filter.
UHF: Components C584 and C491 match the input impedance of the ABACUS III to the IF Filter.

3.1.2.2.2 Second Local Oscillator

The second LO is controlled by the Abacus LO synthesizer, which mixes with IFIN to produce a

2.25 MHz final IF. The external VCO consists of Q550 and its bias network and frequency­determining elements. Signal FREF is the 16.8 MHz reference from the FGU. Darlington transistor
Q551 with C583 and R552 form an active power-line filter.

The second LO frequency is 42.6 MHz (VHF) and 71.1 MHZ (UHF) by default, or 47.1 MHz (VHF)
and 75.6 MHz (UHF) in special cases as needed to avoid radio self-quieters. The loop filter is
composed of R551, C551, C552, and C553.

3.1.2.2.3 Sampling Clock Oscillator

The Abacus sampling clock synthesizer operates at 18 MHz = 8 x 2.25 MHz. The VCO uses an
internal transistor and external resonator. The resonator is composed of L570, C573, and D570.

The loop filter is composed of R571, C570, C571, and C572.

May 28, 2008 6871620L01-C

Theory of Operation: Transceiver Section 3-7

3.1.3 Transmitter

The transmitter takes modulated RF from the FGU and amplifies it to the radio's rated output power
to produce the modulated transmitter carrier at the antenna.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

transmitter-related schematics that will aid in the following discussion.

The transmitter (see Figure 3-5) consists of an RF driver IC that receives its input signal from the
voltage-controlled oscillator (VCO) and a high-power output transistor. Transmitter power is
controlled by a power-control IC (PCIC) that senses the total current drawn by the transmit gain
stages and adjusts PA control voltages to maintain a constant power level. The signal passes
through an antenna switch and harmonic filter to the antenna.

RAWB+

Modulated
RF from FGU

3.1.3.1 Power Distribution

To minimize voltage drop to the power amplifiers, net RAWB+ connects to power module Q107 and
the second stage of driver amplifier U102 through components having minimal series resistance –
ferrite beads and chokes only. During receive, no RF or DC bias is applied, and leakage current
through U102 and Q107 is less than 100 microamps.

At a transmitter power of 2 Watts, the radio consumes approximately 1100 mA.

Sense
Resistor

Driver
Amplifier

Secondary

Cutback

INT

RFIN

Power
Amplifier

PCIC

Figure 3-5. Transmitter Block Diagram

Antenna

Switch

RAWB+

Antenna

Harmonic

Filter

3.1.3.2 Driver Amplifier

The driver amplifier IC (U102) contains two LDMOS FET amplifier stages and two internal resistor
bias networks. Pin 16 is the RF input. Modulated RF from the FGU, at a level of +3 dBm ±2 dB, is
coupled through a blocking capacitor to the gate of FET-1. An LC interstage matching network
connects the first stage output VD1 to the second stage input G2. The RF output from the drain of
FET-2 is pin 6 (RFOUT1). Gain control is provided by a voltage applied to pin 1 (VCNTRL). Typical
output power is about +26 dBm (400 mW) with VCNTRL at 4.5 V.

L101 and C102 are the interstage matching network; capacitor C111 is a DC block.

VHF: Components C112–C115 and L103–L104 match the output impedance to maximize power
transfer to Q107.
UHF: Components C114 and L113 match the output impedance to maximize power transfer to Q107.

6871620L01-C May 28, 2008

3-8 Theory of Operation: Transceiver Section

3.1.3.3 Power Amplifier Transistor Q107

The power amplifier transistor, Q107, is an LDMOS FET housed in a high-power, surface-mount
package. To prevent thermal damage, it is essential that the heat sink of the power module be held in
place against the radio chassis. The input impedance-matching network uses discrete inductors and
capacitors. The low-pass output matching network uses lumped LCs. Drain bias is applied through
E101, R130 and L105. Gain is dynamically controlled by adjusting the gate bias. The gate is
insulated from the drain and source so that gate bias current is essentially zero. Gate bias is applied
through R102, R105, and R106.

VHF: The input and output impedance-matching networks consist of C112–C115, C120–C124,
L103–L104, L106–L108.
UHF: The input and output impedance-matching networks consist of C114, C120–C122, C124,
C141, L108 and L113.

3.1.3.4 Antenna Switch

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

schematics that will aid in the following discussion.

The antenna switch is a single-pole, double-throw, positive-intrinsic-negative (PIN) diode, transmit/
receive (T/R) antenna switch. Forward DC bias (via Q104) turn the diodes ON, reverse or zero bias
turns them OFF.

VHF: PIN diodes D707 and D717 form a narrow-band, quarter-wave, T/R switch.
UHF: PIN diodes D701 and D702 form a narrow-band, quarter-wave, T/R switch.

In transmit mode, both diodes are forward-biased, and the signal goes from the transmitter to the
antenna through the low resistance of the series PIN diode, while the low resistance of the shunt
diode shorts the receiver. In receive mode, neither diode is biased and both behave as small-value
capacitors, creating a high blocking impedance, in effect disconnecting the transmitter circuitry from
the antenna.

3.1.3.5 Harmonic Filter

The harmonic filter is a high-power, low-loss, low-pass filter. Its purpose is to suppress transmitter
harmonics. The filter also improves receiver out-of-band rejection. Shield SH07 must be in place to
achieve the required stop band rejection. The harmonic filter uses discrete components.

VHF: The pass band is up to 190 MHz, and the stop band is above 260 MHz.
UHF: The pass band is up to 490 MHz, and the stop band is above 760 MHz.

May 28, 2008 6871620L01-C

Theory of Operation: Transceiver Section 3-9

3.1.3.6 Power-Control IC (PCIC) U104

The PCIC, U104, contains all of the digital, and most of the analog, circuits needed to control the
transmitter power amplifier. Host control is through a 3-wire, smart SPI interface. Pin descriptions are
shown in Table 3-3.

Table 3-3. Power Control IC (U104) Pin Descriptions

Pin Name Description

1 RFIN Detector voltage input to ALC

2 T1 Test point

3 CI External capacitor for integrator time constant

4 INT Integrator output; control voltage to amplifiers

5 CJ External capacitor for PA rise and fall times

6, 7 VL, CL External capacitor for PA rise and fall times

8 GND1 GROUND

9 F168 Reference clock input, 2.1 MHz

10, 13 QX, CQX External capacitor for voltage multiplier

11, 12 Q, CQ External capacitor for voltage multiplier

14 V10 Voltage multiplier output

15 VG Internal band-gap reference voltage

16 V45 Regulated 4.5 Vdc output

17 V5EXT Power supply input for internal voltage regulator

18 VAR2 Buffered D/A output

19 VLIM Test point for internal D/A No.2 voltage

20 VAR1 Buffered D/A output

21 RS Asynchronous reset input

22 NA Spare pin

23 RX RX/TX mode control-bit output

24 VAR3 Buffered D/A output

25 GND2 GROUND

26 CLK SPI clock input

27 BPOS Power supply input

28 DATA SPI data input/output

29 CEX SPI chip select input

30 TEMP Temperature sensor input

31 RSET External resistor; used to set the temperature cutback rate

32 ANO Switched BPOS output

6871620L01-C May 28, 2008

3-10 Theory of Operation: Transceiver Section

3.1.3.6.1 Power and Control

Since U104 is powered from switched B+, it makes its own regulated 4.5 Vdc to power the internal
logic. The supply input is V5EXT at pin 17, and the output is V45 at pin 16. RX at pin 23 is the control
signal to the antenna switch control circuit.

3.1.3.6.2 Voltage Multiplier

The PCIC contains an internal voltage multiplier. This multiplier produces signal V10 (pin 14), a 10-V
supply for the PCIC D/A converters (DACs). This enables the DACs outputs to reach 8 V. The FREF
signal is a 2.1 MHz clock used to switch the multiplier. The voltage multiplier is not used in the radio.

3.1.3.6.3 Automatic Level Control (ALC)

In TX mode, the PCIC disables the receiver, turns on the transmitter, and controls the TX power
level. The automatic level control (ALC) circuit operates as follows:

The power level is set by programming an internal DAC to a calibrated reference voltage. D/A
settings for the power set points were determined during radio tuning and stored in Flash ROM. An
internal op-amp compares the D/A reference voltage to the detector voltage at pin 1(RFIN) and
produces an error signal output. This signal is buffered by another op-amp, configured as a low-pass
filter, or integrator, to produce the INT output at pin 4 (TP104). This signal drives the base of voltage
follower Q101.

Transistor Q101 supplies current to drive the gain control pins of amplifiers U102 and Q107.
Resistors R105 and R106 determine the voltage ratio between U102 pin 2 (VCNTRL) and the Q107
gate. Transient response during key-up and key-down is controlled by the power amplifier rise and
fall times. External capacitors at pins CI, CJ, and CL, along with internal programmable resistors,
determine the ALC time constants.

3.1.3.6.4 Temperature Cut Back

The PCIC contains a temperature cut-back circuit to protect the power amplifier (PA) from thermal
damage that might result from incorrect assembly of the radio. External sensor U103 is a linear
temperature-to-voltage transducer, placed near the hottest spot in the radio: power module Q107.
The output is a DC voltage at pin 2 (VOUT) proportional to the temperature at pin 3 (GND). VOUT is
750 mV at 25°C and increases by 10 mV/°C. The PCIC temperature cut-back threshold is
programmed to correspond to 85 or 90°C. Above this threshold, the ALC gradually cuts back the
transmitter until it is fully turned off at 110°C. The slope of cut-back versus temperature is set by
external resistor R111. Diode D104 clamps TEMP to a voltage not much less than VG (pin 15), about

1.3 V, to improve the transient response of the cut-back circuit. A secondary temperature cut back
circuitry is also included for enhanced thermal protection due to the small form factor of the radio.
Q102 along with RT150 and the surrounding support circuitry realizes the circuit. This extra
protection acts independently of the cut-back circuit within the PCIC and ensures the radio's
conformance to thermal safety limits.

3.1.3.6.5 D/A Outputs

In RX mode, the PCIC shuts down the transmitter, turns on the receiver, and tunes the RX front-end
pre-selector filters.

Signal VAR2 supplies the voltage used to tune both front-end pre-selector and post-selector filters.
The voltage range varies from 0.8 V to 2.2 V across the VHF band.

May 28, 2008 6871620L01-C

Theory of Operation: Transceiver Section 3-11

3.1.4 Frequency Generation Unit (FGU)

The frequency-generation function is performed by several ICs; multiple, discrete, voltage-controlled
oscillators (VCOs); and associated circuitry.

VHF: The reference oscillator provides a frequency standard to the fractional-N frequency
synthesizer (FracN) IC, which controls the VCOs and VCO buffer IC (VCOBIC). The VCOBIC
amplifies the VCO signal to the correct level for the next stage.
UHF: The reference oscillator provides a frequency standard to the fractional-N frequency
synthesizer (FracN) IC, which controls the VCOs and VCO discreet buffer. The buffer amplifies the
VCO signal to the correct level for the next stage.

Two VCOs are employed – one to generate the first LO and the other to generate the transmit­injection signals.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

FGU-related schematics that will aid in the following discussion.

3.1.4.1 Reference Oscillator Y200

The radio's frequency stability and accuracy derive from the Voltage-Controlled Temperature­Compensated Crystal Oscillator (VCTCXO), Y200. This 16.8 MHz oscillator is controlled by the
voltage from the WARP pin of the FracN (fractional-N frequency synthesizer) IC, U202, that can be
programmed through a serial peripheral interface (SPI). The oscillator output at pin 3 is coupled
through capacitor C234 to the FracN synthesizer reference oscillator input and through C236 to the
non-invertive input of the op-amp, U201.

Op-amp U201 buffers the 16.8 MHz output to the VOCON section. Components L205 and C214
form a low-pass filter to reduce harmonics of the 16.8 MHz.

The Digital-to-Analog Converter (DAC) IC, U203, and Switched Capacitors Filter (SCF) IC, FL200,
form the interface between radio's DSP and the analog modulation input of the FracN IC.

3.1.4.2 Fractional-N Frequency Synthesizer (FracN) IC U202

The FracN IC, U202, is a mixed-mode, Motorola-proprietary, CMOS, fractional-N frequency
synthesizer with built-in dual-port modulation. The XTS 4000 radio uses a low-voltage version of the
device, sometimes called LVFracN, for compatibility with the 3 V logic used throughout the radio.

The FracN IC incorporates frequency division and comparison circuitry to keep the VCO signals
stable. The FracN IC is controlled by the MCU through a serial bus. All of the synthesizer circuitry is
enclosed in rigid metal cans on the transceiver board to reduce interference effects.

Separate power supply inputs are used for the various functional blocks on the IC. Inductors L203
and L204 provide isolation between supply pins 20 (AVDD) and 36 (DVDD) connected to V3A. Host
control is through a three-wire, smart SPI interface (pins 7, 8, and 9) with a bi-directional data pin.
FracN functions include frequency synthesis, reference clock generation, modulation control, voltage
multiplication and filtering, and auxiliary logic outputs.

3.1.4.2.1 Synthesizer

Frequency synthesis functions include a dual-modulus prescaler, a phase detector, a programmable
loop divider and its control logic, a charge pump, and a lock detector output. Fractional-N synthesizer
IC principles of operation are covered in detail in the manufacturers' literature. No similar discussion
will be attempted here.

3.1.4.2.2 Clocks

U202, pin 23 (XTAL1), is the 16.8 MHz reference oscillator input from the VCTCXO (Y200).

6871620L01-C May 28, 2008

3-12 Theory of Operation: Transceiver Section

3.1.4.2.3 Modulation

To support many voice, data, and signaling protocols, XTS 4000 radios must modulate the
transmitter carrier frequency over a wide audio frequency range, from less than 10 Hz up to more
than 6 kHz. The FracN supports audio frequencies down to zero Hz by using dual-port modulation.
The audio signal at pin 10 (MODIN) is internally divided into high- and low-frequency components,
which modify both the synthesizer dividers and the external VCOs through signal MODOUT (pin 41).
The IC is adjusted to achieve flat modulation frequency response during transmitter modulation
balance calibration using a built-in modulation attenuator.

3.1.4.2.4 Voltage Multiplier and Superfilter

Pins 12 (VMULT3) and 11 (VMULT4) together with diode arrays D201 and D202 and their associated
capacitors form the voltage multiplier. The voltage multiplier generates 11.5 Vdc to supply the phase
detector and charge-pump output stage at pin 47 (VCP).

The superfilter is an active filter that provides a low-noise supply for the VCOs and VCOBIC. The
input is regulated 5 Vdc from V5A at pin 30 (SFIN). The output is superfiltered voltage FSF at pin 28
(SFOUT).

The output from pin 15 (VMULT1) is used as a clock for the SCF IC, FL200.

3.1.4.3 Loop Filter

The components connected to pins 43 (IOUT) and 45 (IADAPT) form a 3rd-order, RC low-pass filter.
Current from the charge-pump output, IOUT, is transformed to voltage VCTRL, which modulates the
VCOs. Extra current is supplied by IADAPT for rapid phase-lock acquisition during frequency
changes. The lock detector output pin 4 (LOCK) goes to a logic “1” to indicate when the phased-lock
loop is in lock.

3.1.4.4 VCO Buffer IC (VCOBIC) – VHF only

The VCOBIC (U302) is an analog IC containing two NPN transistors for use as oscillators, an
active-bias circuit, transmitter and receiver buffer amplifiers, and switching circuitry. The VCOBIC
has three RF outputs:

• TX_OUT (pin 10) – the modulated transmitter carrier

• RX_OUT (pin 8) – the receiver first LO

• PRESC_OUT (pin 12) – connected to FracN pin 32 (PREIN) through a matching circuit

Transmit/receive control is a single 5.0 Vdc logic input, TRB_IN (pin 19). When TRB_IN is low, the
receiver buffer is active and the transmitter circuits are disabled. The converse is also true.

The VCOs in VHF radios use the VCOBIC internal transistors and implement the active bias via
resistors R304 and R305. Bias to TX_OUT is supplied through resistor R313. Components L309 and
C316 form a matching circuit for the TX_OUT impedance. C315 acts as a DC block, and resistors
R314, R315, and R316 attenuate an output signal to an optimum level for the PA.

L312 form a low-pass bias supply filter for the RX_OUT. L310 and C317 are the RX_OUT
impedance-matching circuit. C322 is a DC block, and resistors R317 and R318 attenuate an output
signal to an optimum level for the mixer IC.

An NPN/PNP-packaged transistor, Q310, together with the supporting components R310 and C330,
form the 3.3 Vdc-to-5 Vdc logic-level shifter between the AUX3 pin of the FracN IC, U202, and
VCOBIC, U302.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-13

3.2 VOCON Section

This section provides a detailed circuit description of the ASTRO XTS 4000 VOCON section.

The VOCON section (see see Figure 3-6) is divided into the following sections:

• Controller and Memory

• Audio and Power

• Accessory and CE Interface Connector Support

3.2.1 Connections

The VOCON section (see Figure 3-6) contains three functional blocks and three connector symbols.

MAKO

SSI

SPI

Earpiece

60 pins

Loud Speaker

Audio Jack

30 pins

CE

Connector

30 pins

RTC

DA or AD
Converter

DC Regulators

Accessory

Interface

Audio P.A.

Voice Codec

Power

Management

Figure 3-6. VOCON Section Connections

The functional blocks consist of the following:

I/O

VOCON

CONTROLLER AND MEMORY

FLASH

8 MBytes

Dual-Core
Processor

MCU and DSP

SRAM

4 MBytes

Encryption

Module
30 pins

XCVR

Display &

Keypad

60 pins

Controls &

Buttons
16 pins

• Controller and Memory: The Patriot (U1401), the dual-core processor with the microcontroller

unit (MCU) and a digital signal processor (DSP), the 4MB SRAM (U1409) and 8MB Flash
(U1410) memory devices.

• Audio and Power: The MAKO IC (U1304), a 5Vdc linear regulator (U1101), an audio switch IC

(U20) and a single-ended gain stage (U9904)

• Accessory and CE Interface Connector Support: The MAKO IC (U1304), ESD protection

circuitry, and CE connector interface circuitry.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

VOCON schematics that will aid in the following discussion.

6871620L01-C May 28, 2008

3-14 Theory of Operation: VOCON Section

3.2.1.1 Connector J1 (Display and Keypad)

This is a 60-pin connector that mates with the Front-Flip flex on the front housing. The 60
connections on the connector J1 consists of Display (control and data) lines (28), Keypad lines (15),
Earpiece audio lines (2), DC supplies and radio GROUND connections.

3.2.1.2 Connector J2 (Encryption Module, CE Interface Connection and Audio Jack Connection)

This 30-pin connector mates with the UCM-CE-Audio Jack flex and provides the connections from
the VOCON section to the Encryption Module, the CE Accessory Interface and the 2.5mm Audio
Jack.

Two voltages are provided to the encryption module: UNSWB+ and SWB+. The SAP SSI lines, serial
communication data lines and general purpose I/O lines from the Patriot IC are routed through this
connector.

Connections to the CE accessory connector, which include serial data communication and UCM are
present at pins 18 and 17.

The external audio jack consists of a microphone, audio jack interrupt, PTT line and single-ended
audio.

3.2.1.3 Connector J3 (Buttons and Controls Connection)

This 16-pin connector mates the VOCON section (on the mainboard) to the volume controls and
user buttons (PTT, EMERGENCY, SECURE mode and programmable buttons etc.).

3.2.2 Controller and Memory

The controller and memory section contains the following components:

• Patriot IC (U1401)

• Static RAM (SRAM) IC (U1409)

• Flash memory IC (U1410)

The Patriot IC acts as both the microcontroller unit (MCU) and the digital signal processor (DSP) for
the radio. The MCU controls receive/transmit frequencies, power levels, display programming, user
interface (PTT, keypad, menu select, etc.), and programming of ICs, as well as other functions. The
DSP performs voice encoding and decoding, audio filtering, volume control, PL/DPL encode and
alert-tone generation, squelch control, and receiver/transmitter filtering, as well as other functions.

The Patriot IC executes a stored program located in the Flash memory device. The SRAM, a volatile
device, is used as working memory and shares the address and data bus with the Flash memory
device.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of

VOCON schematics that will aid in the following discussion.

3.2.2.1 Patriot IC U1401

The Patriot IC U1401 is a dual-core processor that contains both a 32-bit microcontroller unit (MCU)
and a 16-bit digital signal processor (DSP) in one IC package. It comes in a 256-pin, ball-grid array
(BGA) package with 0.3mm pitch solder balls. The dual-core processor is supplied with two voltages:

1.875 V and 1.55 V. The 1.55 V supply is used as the core voltage while the 1.875V is used as the
interface to the memory devices and display module. Most of the pins on the Patriot IC operate from
the 2.9 V supply.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-15

Two main clocks are provided to the Patriot IC. The CKIH pin (C1402) is provided a 16.8 MHz sine
wave. This is the most important clock since it is internally used to generate the clocks for both the
MCU and DSP cores, as well as most of the peripherals. A 3 V peak-to-peak 32 kHz square wave
(32 kHz test point) is generated by the oscillator Y1301 and the buffer U1301, and supplied to the
CKIL pin on the Patriot IC. While not as widely used as the 16.8 MHz clock, the 32 kHz clock is
needed by some components in the Patriot including the reset circuitry.

3.2.2.1.1 Microcontroller Unit (MCU)

The MCU portion of the Patriot IC has 16k x 32 bits of internal RAM and 28k x 32 bits of internal
ROM, which is used for the bootstrapping code. The MCU has several peripherals including an
External Interface Module (EIM), the Multiple Queue Serial Peripheral Interface (MQSPI), two
Universal Asynchronous Receiver/Transmitter (UART) modules, and the One-Wire Interface
module. The MCU communicates internally to the DSP through the MCU/DSP Interface (MDI).

External Interface Module (EIM)

The External Interface Module (EIM) is the MCU interface to the SRAM U1409 and Flash Memory
U410, as well as the display module. The EIM lines include 24 external address lines, 16 external bi­directional data lines, 6 chip selects lines, read/write line, and output enable line among others. All of
the EIM lines operate at 1.875-V logic levels, and the EIM operates at the MCU clock speed.

Multiple Queue Serial Peripheral Interface (MQSPI)

The Multiple Queue Serial Peripheral Interface (MQSPI) is the MCUs programming interface to other
ICs. The Patriot IC has two independent SPI busses, and each has its own clock line (test points
SCKA and SCKB), data-out line (test points MOSIA and MOSIB), and data-in line (test points MISOA
and MISOB). There are 10 SPI chip selects (SPICS) that are programmable to either SPI A, the
transceiver board SPI bus, or to SPI B, the dedicated VOCON SPI bus.

The devices on the SPI A bus include the PCIC and FracN IC on the SPICS4 (R1118), the Abacus III
IC on SPICS5 (R1119), and an analog-to-digital converter (ADC) on SPICS6 (R1120). One SPI B
chip select is used for the MAKO IC (U1304). All of the SPI module lines operate at GPIO voltage
logic levels.

Universal Asynchronous Receiver/Transmitter (UART)

The Patriot IC has two Universal Asynchronous Receiver/Transmitter (UART) modules. UART1
handles the RS232 lines while UART 2 is connected to the SB9600 lines. Each UART has a receive
data line (URXD), a transmit data line (UTXD), and hardware flow control signals (RTS–request to
send) and (CTS–clear to send). All UART lines operate at GPIO voltage logic levels. The translation
to 5 V logic levels for the accessory side connector is discussed in the MAKO section.

One-Wire Interface

The MCU has a One-Wire Interface module that is used to communicate to a One-Wire device like a
USB cable or a smart battery using the Dallas Semiconductor protocol. This module uses a GPIO
voltage logic level.

6871620L01-C May 28, 2008

3-16 Theory of Operation: VOCON Section

3.2.2.1.2 Digital Signal Processor (DSP)

The DSP portion of the Patriot IC has 84k x 24 bits of program RAM and 62k x 16 bits of data RAM.
The DSP has its own set of peripherals including the Baseband Interface Port (BBP), the DSP Timer
module, and the Serial Audio CODEC Port (SAP). Additionally, the DSP shares some peripherals
with the MCU, including the USB interface and the General Purpose Input/Output module (GPIO).

Baseband Interface Port (BBP)

The Baseband Interface Port (BBP) module is the DSP’s serial synchronous interface (SSI) to the
transceiver section. The BBP has independent sections for the receiver and the transmitter. The
receiver BBP pins include the receive data pin SRDB (R1110), the receive clock signal pin SC0B
(R11 09), a nd th e rece i ve fr ame sy nchro niza tion ( sync) sign a l pin SC1B ( R1111). T he tra nsmit ter' s
BBP pins include the transmit data pin STDB (R1113), the transmit clock signal pin either SCKB
(R1112), and the transmit frame sync signal pin either SC2B (R1114). All BBP lines use GPIO
voltage logic levels.

DSP Timer Module

While the BBP receive clock and frame sync signals are supplied by the Abacus III IC from the
transceiver section, the BBP transmit clock and frame sync signals are generated by the DSP Timer.
The BBP receive clock, connected to the DSP Timer input pin T10, is reference used to generate the
BBP transmit clock and frame sync signals. These two signals, along with the BBP transmit data
signal, are connected to the DAC on the transceiver section.

Serial Audio CODEC Port (SAP)

The Serial Audio CODEC Port (SAP) module is the DSP’s serial synchronous interface (SSI) to the
audio CODEC on the MAKO IC. The SAP also interfaces with the encryption module.

The SAP interface consists of four signals including the SAP clock line pin SCKA (component
R1410), the SAP frame sync line pin SC2A (component R1411), the SAP receive data line pin SRDA
(component U1408), and the transmit data line pin STDA (component R1338).

The SAP clock is generated by the dual-core processor U1401, and is a 256 kHz, 2.9 V peak-to­peak square wave. The SAP frame sync signal is generated by the dual-core processor U1401, and
is an 8 kHz, 2.9 V peak-to-peak square wave.

Universal Serial Bus (USB)

The Patriot IC USB peripheral, shared by the MCU and the DSP, provides the required buffering and
protocol to communicate on the Universal Serial Bus. The Patriot IC supports USB slave
functionality.

For receive data, the USB differentially decoded data comes from the MAKO IC
USB2_OE_RCV_RTS pin into the Patriot URTS1 pin, while the single-ended USB data positive
signal goes to pin PA2_USB_VPIN, and the single-ended USB data minus signal goes to pin
URXD1. The two data lines are used to detect the single-ended zero state.

For transmit data, the USB data comes out of the Patriot IC UTXD1 pin and goes to MAKO IC
USB1_DAT_TXD pin. The USB transmit single-ended zero signal is generated from the Patriot IC
PC0_USB_VMOUT pin.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-17

General-Purpose Input/Output (GPIO) Module

The General-Purpose Input/Output (GPIO) module is shared by the MCU and the DSP. This module
consists of four 16-pin bi-directional ports and a 15 pin bi-directional port. While some of the pins on
these ports are being used for other functions (UART, SPI, SAP, BBP, and Interrupt pins), the
remaining pins can be programmed to become GPIOs that can be used by either the DSP or the
MCU. Each GPIO pin has up to 8 alternate output functions and up to 4 alternate input functions.
This allows for the GPIO pins to be routed internally to pertinent Patriot IC modules. Additionally, the
GPIO module adds selectable edge-triggered or level-sensitive interrupt functionality to the GPIO
pins. Some examples of GPIO pins include the Display module backlight brightness control signals
(DISP_BRIGHT1 and DISP_BRIGHT2), the Keypad backlight enable signal (KP_BLEN) and the Flip
Assembly Open/Close Sense Signal (FLIP_SENSE).

3.2.2.2 Static RAM (SRAM) U1409

The static RAM (SRAM) IC U1409 is an asynchronous, 4 MB, CMOS device that is capable of 70 ns
access speed. It is supplied with 1.875 volts. The SRAM has its 19 address lines and 16 data lines
connected to the EIM of the Patriot IC through the Address(23:0) and Data(15:0) busses.

The SRAM has an active-high chip select CE2 that is tied directly to the 1.875 V supply and an
active-low chip select EN_CE that is connected to the EIM CS2_N pin. When the SRAM EN_CE pin
is not asserted, the SRAM is in standby mode, which reduces current consumption.

Two other control signals from the EIM that change the mode of the SRAM are the read/write signal,
R/W, and the output enable signal, OE. The R/W of the EIM is connected to the SRAM EN_WE pin,
while the OE signal from the EIM is connected to the SRAM EN_OE pin. The SRAM is in read mode
when the EN_WE pin is not asserted and the EN_OE pin is asserted. The SRAM is in write mode
when the EN_WE pin is asserted, regardless of the state of the EN_OE pin.

The other SRAM pins are the lower-byte enable pin EN_BLE and the upper-byte enable pin
EN_BHE. These pins are used to determine which byte (BLE controls data lines 0-7 and BHE
controls data lines 8-15) is being used when there is a read or a write request from the Patriot IC.
The EN_BLE pin is controlled by the EIM EB1_N signal, while the EN_BHE pin is controlled by the
EB0_N signal.

3.2.2.3 FLASH Memory U1410

The Flash memory IC is an 8 MB CMOS device with simultaneous read/write or simultaneous read/
erase operation capabilities with 70 ns access speed. It is supplied with 1.875 volts. The Flash
memory has its 23 address lines and 16 data lines connected to the EIM of the Patriot IC through the
Address(23:0) and Data(15:0) busses. The Flash memory contains host firmware, DSP firmware,
codeplug data and the transceiver section's tuning values. The Flash memory IC is not field
repairable.

The RESET_OUT of the Patriot IC is at a GPIO voltage logic level. Components D1401 and R1437
are used to convert the voltage down to a 1.875 V logic level, and this 1.875 V reset signal is fed to
the Flash RESET pin. When this pin is asserted (active low logic), the Flash is in reset mode. In this
mode, the internal circuitry powers down, and the outputs become high-impedance connections.

The Flash active-low chip select pin, EN_CE, is connected to the active-low CS0_N pin (CS0 test
point) of the EIM. When the EN_CE is not asserted, the Flash is in standby mode, which reduces
current consumption.

6871620L01-C May 28, 2008

3-18 Theory of Operation: VOCON Section

Several other active-low control pins determine what mode the Flash memory is in: the address valid
pin ADV that is connected to the EIM LBA_N signal, the output enable pin EN_OE that is connected
to the EIM OE_N signal, and the write enable pin EN_WE that is connected to the EIM EB1_N
signal. For read mode, the ADV and EN_OE pins are asserted while the EN_WE pin is not asserted.
When the EN_WE is asserted and the EN_OE pin is unasserted, the Flash operates in the write
mode.

Figure 3-7 illustrates the EIM and memory ICs block diagram.

RESET_OUT

LBA_N

CS0_N

EB1_N

OE_N

Voltage

Translator

CSO

A(23:1)

Dual-Core

Processor

U1401

A(23:0)

D(15:0)

EB0_N

CS2_N

RW_N

A(19:1)

CS2

R_W

Figure 3-7. Patriot EIM and Memory Block Diagram

RESET

ADV

EN_CE

EN_WE

EN_OE

A(22:0)

D(15:0)

A(18:0)

D(15:0)

EN_OE

LB

UB

CS1

EN_WE

Flash

U1410

SRAM

U1409

MAEPF-27414-B

3.2.3 Audio and Power

The audio and power section contains the following components:

• MAKO IC U1304

• 5 V regulator U1101

• Audio Switch U20

• Single-ended Audio Gain stage U9904

The MAKO IC contains a CODEC, amplification, filtering and multiplexing capability for receive and
transmit audio, voltage regulators, an analog-to-digital converter (ADC), and a real-time clock (RTC).
The MAKO IC is programmed by the Patriot IC.

The MAKO IC also contains an audio preamplifier and an audio power amplifier to condition the
received audio signal. Programmable preamplifiers also sets the gain of the microphone audio
signal. These devices internal to the MAKO are programmed by the Patriot IC.

NOTE: Refer to Table 8.1, “List of Schematics and Boards Overlays,” on page 8-1 for a listing of audio

and power-related schematics that will aid in the following discussion.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-19

3.2.3.1 MAKO IC U1304

The MAKO IC is a mixed-signal (analog and digital) IC that provides control, audio, and voltage
regulation functionality. It comes in a 176-pin, ball-grid array (BGA) package with 0.8 mm pitch solder
balls. The MAKO IC is supplied with switched battery voltage UNSW_B+ (R1309).

3.2.3.1.1 Voltage Regulation

The MAKO IC contains several voltage regulators that are used in the design of the VOCON section:
VSW1, V2, VCC5, V1.55 and V1.875. The VSW1 regulator is a programmable switching regulator
that uses the switched battery voltage as its input. The output voltage of VSW1 (R1319) is
programmable by the Patriot IC U1401 through the SPI bus. The initial output of VSW1 is 3.2 volts,
which is then programmed to 3.8 volts. The VSW1 voltage is supplied to the RF transceiver section
and to the input pins of the V2 regulator.

The V2 regulator is a SPI programmable linear regulator that uses VSW1 as its supply. The initial
output of V2 (L1302) is 2.775 volts, which is then programmed to 2.9 volts for the VOCON section.
The V2 voltage is supplied to the Patriot IC (I/O ring - SPI, BBP, SAP, UART, GPIO, etc.), the display
module via connector J1, and the many discrete components that interface with the Patriot IC and
the MAKO IC.

The VCC5 regulator is a fixed linear regulator that outputs 5Vdc. VCC5 is used by the accessory I/O
lines and the audio switch U20.

The V1.55 is a SPI programmable linear regulator. V1.55 is used by the Patriot MCU Core. The
V1.875 is a SPI programmable linear regulator. V1.875 is used by the EIM, Memory, Display and I/O
ring.

3.2.3.1.2 MCU Interface

The MAKO IC has a four-wire, SPI connection to the Patriot IC (SPI B). The SPI B clock is connected
to the SPI_CLK pin (SCKB). The SPI B MOSI line is connected to the SPI_DI pin. The SPI B MISO
line is connected to the SPI_DO pin. The MAKO SPI B chip-select signal is connected to the SPI_CS
pin (R1334). Through this interface, the Patriot IC can program the voltage regulators, the CODEC,
the transmit and receive audio filters and amplifiers, as well as read information from the ADC and
the real-time clock.

The MAKO IC has an 10-bit ADC with 11 channels. Some of the ADC channels are used for general
purpose voltage monitoring: Emergency Button (ATOD_2), board type (ATOD_5) and the board
identification voltage (ATOD_6). Battery voltage is also monitored by the ADC. The Patriot IC
activates and reads the A/D values through the SPI bus.

3.2.3.1.3 Audio Circuitry

A 16-bit CODEC, internal to the MAKO IC and programmable by the Patriot IC through the SPI bus,
converts microphone audio into a digital bit stream for processing by the DSP. The CODEC also
converts receive audio data that was processed by the DSP into an analog audio signal for
amplification to a speaker. The CODEC interfaces to the DSP through the 4-wire SAP bus. The
CODEC clock, which is 256 kHz is supplied to the DCLK pin. The CODEC 8 kHz CODEC frame
synchronization signal is supplied to the FSYNC pin. The CODEC transmit data signal is on the TX
pin, while the CODEC receive data signal is on the RX pin. For the CODEC to operate with those
clock and frame sync signals, a 24.576MHz clock, generated by Y1302 is supplied to the MAKO IC.

The MAKO IC contains internal amplification, filtering, and multiplexing functionality for both receive
and transmit audio. These functions are Patriot IC-programmable through the SPI bus. The input for
the internal microphone audio (C1350) is the INT_MIC_P pin, while the input for the external
microphone audio (C1347) is the EXT_MIC_P pin.

6871620L01-C May 28, 2008

3-20 Theory of Operation: VOCON Section

The MAKO contains two internal audio power amplifiers for internal and external speaker routing and
the outputs are available at pins INT_SPKR_P and INT_SPKR_M (internal speaker) and
EXT_SPKR_P and EXT_SPKR_M (external speaker). Section 3.2.5.2 on page 3-27 details the
audio routings to the various transducers. The audio routing selection is controlled by the Patriot IC.

3.2.3.2 5 V Regulator U1101

The 5 V regulator, U1101, uses UNSW_B+ as its input voltage. This regulator supplies 5Vdc to the
keypad circuitry, the radio ON/OFF circuitry and the display backlight control circuitry.

3.2.3.3 Audio Switch U20

The audio switch U20 is a single-pole, double-throw analog switch that switches amplified audio from
the MAKO external speaker terminals (EXT_SPKR_P and EXT_SPKR_M) to the earpiece (on the
flip assembly) or the single ended audio gain stage for the 2.5mm audio jack earpiece. The U20 is
supplied from VCC5.

3.2.3.4 Single-Ended Audio Gain Stage U9904

U9904 is the single-ended audio gain stage for the 2.5mm audio jack earpiece. It consists of a non­inverting operational amplifier and DC biasing circuitry. One of the outputs of the audio switch (U20)
is channelled to U9904.

3.2.4 Accessory and CE Interface Connector Support

The accessory and CE interface connector support section consists of the following:

• MAKO IC U1304

• ESD protection circuitry

• CE connector interface circuitry

The MAKO IC contains a RS232 and USB transceiver, switching logic between RS232 and boot data
path, One-Wire side connector support, and several supporting circuitry. The MAKO IC is
programmed by the Patriot IC.

ESD protection devices include zener diodes and low-capacitance ESD suppressors.

CE interface connector circuitry includes current-limiting resistors and noise-suppressing shunt
capacitors.

3.2.4.1 MAKO IC U1304

See Figure 8-14, “VOCON: DC Power, Clocks and ON/OFF Circuit,” on page 8-15 for schematic

details of the following discussion.

The MAKO IC U1304 also contains the circuitry and blocks to support radio accessories and test/
programming service aids. The block supports many functions including radio CE connector
interface, bi-directional logic level translation, boot data path control, USB transceiver and One Wire
option detect support.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-21

3.2.4.1.1 Radio CE Connector Interface, Logic Level Translation, and Boot Data Path Control

The MAKO IC facilitates the interface to the radio's CE connector. Some of the CE connector lines
are at 5 V logic levels, so the MAKO IC converts those lines to GPIO voltage logic levels to interface
to the Patriot IC, as well as the encryption module. These lines include the SB9600 bus busy line
LH_BUSY, the RS 232 CTS and RTS lines, the RS232 data-out line, and the RS232 data-in line.

Another function that the MAKO IC provides with these lines is boot data path control. The boot data
path is as follows: boot data-in is multiplexed onto the RS232 data-out line while the boot data-out is
multiplexed with the SB9600 data line. This alternate data path is used only to Flash code into a
radio for the first time. The Patriot IC, through the SPI bus, controls this feature.

3.2.4.1.2 USB Transceiver

The USB transceiver, internal to the MAKO IC, is capable of transmitting and receiving serial data at
a rate of 12 megabits per second. The differential USB data comes from the CE connector, through
the 33-ohm resistors R1206 and R1207, and then to the USB1_DP and USB1_DM pins on the
MAKO IC. The USB receive interface from the MAKO IC to the Patriot IC is as follows: USB1_DP
routed to USB1_DAT_TXD, USB1_DM routed to USB2_SE0_VM_RXD.

The USB transmitter is enabled when the RS232_USB and USB_TXENAB signals are both driven
low by the Patriot IC. The single-ended data is output from the Patriot IC on the UTXD1_USB_VPO
pin and goes to the MAKO USB1_DAT_TXD pin. The data is driven out differentially on the
USB1_DP and USB1_DM, which go to the CE connector. The Patriot IC sends the single-ended
zero signal from pin USB_VMO to the MAKO IC USB1_SE0 pin.

When a USB cable is attached, pin CTS_CABLE_DET_5V is driven low and goes through level
translation in U701 and the output of CTS_CABLE_DET_3V is pulsed low and sent to the dual-core
processor. This line controls the USB and RS232 modes so that the data that is on those lines are
routed to the USB transceiver when a cable is detected. If a USB cable is not detected,
CTS_CABLE_DET_3V is high, the USB transceiver is put in suspend mode and the DP and DM pins
can now handle 5V tolerance for RS232 mode of operation.

3.2.4.1.3 One-Wire Support

New options and accessories that attach to the CE connector are identified by the Patriot IC using
the One-Wire protocol. The Option Select 2 pin on the CE connector also serves as the One-Wire
data pin. This signal is connected to the ONE_WIRE_OPT pin. This pin is connected to the dual-core
processor one-wire bus (ONE_WIRE_UP) through the MAKO IC internal isolation switch which is
controlled by the SPI commands sent from the dual-core processor. This isolation is needed to
prevent possible contention on the One-Wire bus when a smart battery is attached to the radio.

These new accessories are to GROUND pin CTS, of the CE connector. When this occurs, the MAKO
IC pin ONE_WIRE_OPT is asserted and the Patriot IC detects the change. The Patriot IC then
instructs the MAKO IC (via SPI) to connect the CE connector One-Wire line to the Patriot IC One­Wire bus. In the case of the USB cable, the Patriot IC reads the One-Wire data from the cable and,
upon determining that a USB cable is attached, programs the MAKO IC for USB mode.

3.2.4.1.4 Watchdog Timer

The watchdog timer is a 125ms counter that is integrated into the MAKO IC and used during the
power down sequence. The MAKO IC will begin the power down sequence when a low-to-high
transition occurs on MECH_SW pin. Once this transition occurs, the MAKO IC begins the watchdog
timer. Upon expiration of the timer, the RESETX pin is asserted and all MAKO regulators are
shutdown. The dual-core processor can refresh the watchdog timer so that the software has enough
time to complete its tasks before the power is taken away completely.

6871620L01-C May 28, 2008

3-22 Theory of Operation: VOCON Section

3.2.4.1.5 24.576 MHz Reference Generation for MAKO

The 24.576 MHz reference is required by the MAKO IC for the CODEC time base and the SSI clock
generator module internal to the MAKO IC. The clock is generated by crystal oscillator Y1302 and
load capacitors C1316 and C1317.

3.2.4.1.6 SSI Clock and Frame Sync Generator

The MAKO IC generates the SSI clock and frame sync signals for the SAP bus used by the Patriot
IC and encryption module. These signals are generated from the 24.576 MHz reference. The SSI
clock output pin is labeled SSI_CLK, and the frequency is 512 kHz. The SSI frame sync output pin is
SSI_SYNC, and the frequency is 8 kHz. These signals are not active when the MAKO IC comes out
of reset, so they are programmed by the Patriot IC through the SPI bus.

3.2.4.2 ESD Protection Circuitry

See Figure 8-12, “VOCON: Audio, Connector Interface Circuits,” on page 8-13 for schematic details

of the following discussion.

Several components on the VOCON section protect the circuitry from ESD. The CE connector signal
lines have ESD protection components on them since they are exposed. These protection
components include:

• 5.6-V zeners VR1301 on the BAT_STATUS line, 5.6-V zener diode on reset line (UHF), VR1202
and VR1203 on the RS232 and USB data lines

• 6.8V zeners on the OPT_SEL lines, the ONE_WIRE line and the Audio Jack lines

• 12V zeners on the MAKO audio outputs

Spark Gaps are also present on the mainboard layout as a back-up defense mechanism against
ESD.

3.2.4.3 Radio CE Interface Connector Circuitry

See Figure 8-12, “VOCON: Audio, Connector Interface Circuits,” on page 8-13 for schematic details

of the following discussion.

An important circuit in the CE interface connector is the Option Select 2 (OPT_SEL2) line
comparator. The opamp (U1201) is used as a comparator for the option select 2 line. The voltage
divider network of R1227 and R1229 determines the comparator threshold. The remaining
components on the CE interface connector consist of current-limiting serial resistors and noise­suppressing shunt capacitors.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-23

3.2.4.3.1 Radio CE Connector and Option Selects

The CE connector is located on the bottom side of the radio. It is the external port or interface to the
outside and is used for programming and interfacing to external accessories. The CE connector
connects to the VOCON section at connector J2 via a flex circuit (UCM-CE-Audio Jack Flex) that is
routed inside the external housing. Pin assignments on the CE connector are shown in Figure 3-8.

1

CE_GND
CE_NC1

3

CE_OPTB+_VPP

4

CE_RS232_TX_USB+
CE_RS232_RX_USB
CE_RTS
CE_NC2
CE_CTS
CE_LH_DATA_KEYFAIL
CE_EXT_MIC
CE_NC3
CE_NC4
CE_OPT_SEL1
CE_OPT_SEL2
CE_EXTSPKR
CE_SPKRCOM

17

CE_NC5

Most of the signals are extensions of circuits described in other areas of this manual. However, there
are two option select pins (see Table 3-4) used to configure special modes: Option Select 1 and
Option Select 2. These pins are controlled by accessories connected to the universal connector.

Table 3-4 outlines their functions as defined at the universal connector.

External PTT 00

No Function (Normal) 11

External Speaker 01

3.2.4.4 Dual Display Module

The XTS4000 radio has a dual display module within the front-flip assembly of the radio. The dual
display consists of a main display and a caller identification CID display. The main display is a 130 x
130 dot matrix liquid crystal display (LCD) whereas the CID display is a 112 x 32 dot matrix LCD. The
display module uses chip on film technology and is not field repairable.

Figure 3-8. CE Connector

Table 3-4. Option-Select Functions

Function

Option

Select 1

Option

Select 2

3.2.4.5 Keypad

The keypad on the XTS4000 radio is a 3 x 3 Menu Keypad (with 4-way navigation button) and a 3 x
4 alphanumeric keypad. This keypad is realized through a flex circuit design which is housed within
the front-flip assembly of the radio. The keypad is connected to the VOCON section through
connector J1.

6871620L01-C May 28, 2008

3-24 Theory of Operation: VOCON Section

The keypad lines are read through a row and column matrix made up of 7 row lines (UC_KP_ROW0
to UC_KP_ROW6) and 3 column lines (UC_KP_COLUMN0 to UC_KP_COLUMN2). A separate line
connects the ON/OFF button on the keypad to the ON/OFF Circuitry on the VOCON section
(UC_KP_ONOFF)

Keypad backlighting is supplied by the 5V Misc Regulator (U1101) and the backlight is controlled by
the Patriot IC GPIO KP_BLEN.

3.2.4.6 Buttons and Controls

The XTS4000 radio has the following buttons and controls:

• PTT button (PTT)

• Clear/ Secure mode button (P1)

• Emergency button (P2)

• Programmable button (P3)

• Volume Controls (VOL)

The P1, P2 and P3 buttons are connected to a resistor divider network, biased between V2 and
GROUND. The network, made up of R9913, R9914 and R9915 provides a DC voltage level,
controlled by whichever button is pressed, to pin 3 of buffer U1305. The output of buffer U1305 goes
to the MAKO ATOD_2 pin. The Patriot IC reads the MAKO A/D value through the SPI bus and uses
the read data to determine which button was pressed.

The PTT button is connected to the Patriot IC INT0 Interrupt pin for fast action of the Patriot IC to
execute the PTT operation.

Volume controls for the radio are set by up and down controls. These controls share the
UC_KP_COLUMN0, UC_KP_COLUMN1 and UC_KP_ROW7 lines. The Patriot IC uses these three
lines to determine whether the volume up or volume down button was pressed.

Figure 3-9 shows the buttons and controls implementation.

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-25

Top Control Flex

Top Control Flex

UC_EMERG

UC_EMERG

INT_PTT

INT_PTT

R9913 91K

R9913 91K

R9914 68K

R9914 68K

R9915 150K

R9915 150K

EMERGENCY

EMERGENCY

Button

Button

CLEAR/SECURE

CLEAR/SECURE

Button

Button

Programmable

Programmable

Button

Button

PTT Button

PTT Button

UC_KP_COLUMN0

UC_KP_COLUMN0

UC_KP_COLUMN1

UC_KP_COLUMN1

UC_KP_ROW7

UC_KP_ROW7

3.2.4.7 System Clocks

The Patriot is supplied with two clocks:

1. The first clock, a 16.8 MHz sine wave, comes from the RF transceiver portion of the radio. It
is conditioned by the clock buffer circuit, which includes Q1402, R1416, R1417, R1418,
R1415, C1402, C1403 and C1404.

2. The other clock supplied to Patriot is a 32.768 kHz square wave. This clock is generated by
the external 32.768kHz crystal Y1301, and a clock buffer circuit that includes U1302, R1304,
R1305 and C1303. This signal is supplied to the CKIL pin on the dual-core processor.

VOLUME Down

VOLUME Down

Button

Button

Figure 3-9. Control Top Flex

VOLUME Up

VOLUME Up

Button

Button

3.2.5 VOCON Audio Paths

This section describes the VOCON transmit and receive audio paths. See Figure 8-15 and

Figure 8-16 on page 8-16 and page 8-17 for schematic details of the following discussion.

6871620L01-C May 28, 2008

3-26 Theory of Operation: VOCON Section

3.2.5.1 Transmit Audio Path

The single-ended internal microphone audio enters the VOCON section through the 30 pin
connector (J2), and the internal microphone bias is set by circuitry that includes R1324, R1325,
C1349, C1350 and C1351. The internal microphone signal is connected to the INT_MIC_P pin,
which is the input terminal on the MAKO IC internal op-amp G1 after the signal is multiplexed. The
gain is programmed by the dual-core processor via SPI lines.

The external microphone audio enters the VOCON section through the 30 pin connector J2 as well
and the external microphone bias is set by circuitry that includes R1322, R1323, C1346, C1347 and
C1348. The external microphone signal is connected to the EXT_MIC_P pin, which is an input
terminal on the MAKO IC internal op-amp G1 after the signal is multiplexed. The gain is programmed
by dual-core processor via SPI lines.

The dual-core processor, through the SPI bus, programs a multiplexer internal to the MAKO IC to
select one of the microphone signals. Then, the selected microphone signal goes through the G1
pre-amplifier stage and on to a programmable gain amplifier (G2) before it goes to the CODEC for A/
D conversion. The resulting digital data is filtered and sent to the DSP on the CODEC_TX line from
the MAKO IC VC_TX3V pin. After additional filtering and processing, the DSP sends the data out
from the STDB pin, labeled TX_SSI_DATA to the RF transceiver section.

INTERNAL MIC BIAS

R1324, R1325, C1349,

C1360, C1351

EXTERNAL MIC BIAS

R1322, R1323, C1346,

C1347, C1348

INT_MIC_P

MAKO IC

Pre-amp

G1 Gain = 15 dB

Patriot

SAP / BBP

Gain = -30 to 0 dB

CODEC_TX
CODEC_FSYNC
CODEC_DCLK

TX_SSI_FSYNC
TX_SSI_CLK
TX_DATA

EXT_MIC_P

MAKO_CS
SPI_MISOB
SPI_MOSIB
SCKB

MUX

4

Patriot

SPIB

Figure 3-10. VOCON Transmit Audio Path

Amp G2

HPF = 200 Hz

& LPF = 3.4 kHz cutoff

3

CODEC

A/D 16-Bit

RF D/A

U201

May 28, 2008 6871620L01-C

Theory of Operation: VOCON Section 3-27

3.2.5.2 Receive Audio Path

Refer to Figure 3-11. The receive audio data comes from the Abacus III IC (DOUTA) to the dual-core
processor SRDB pin. The DSP decodes the data and sends it out through the CODEC_RX line to
the MAKO IC VC_RX pin. The CODEC filters, adds digital programmable gain G1, then converts the
digital data into an analog audio signal, which in turn is sent to programmable attenuator G3. The
signal is then sent through an internal programmable differential preamplifier (G4). The preamplifier
outputs are on pins VC_OUT_P and VC_OUT_M of the MAKO IC.

This output from the preamp is first filtered through the circuitries R1326, R1327, C1355, C1356 and
C1357, and then sent back to two independent internal BTL differential power amplifiers, G5 & G6, of
the MAKO IC. The power amplifiers are programmed to a fixed gain through the dual-core processor
SPI lines and PA control registers.

The dual-core processor selects whether the amplified audio is routed to the internal speaker or the
external speaker through the SPI lines based upon which amplifier is turned on as shown in the PA
control block. The output audio is routed on MAKO IC pins INT_SPKR_P and INT_SPKR_M for
internal and EXT_SPKR_P and EXT_SPKR_M for external speaker lines. The external audio is then
routed to an audio switch (U20) where it switches the audio between the flip earpiece and the audio
jack earpiece. The logic behind the audio routing is set by the Patriot IC (depending on the user's
operating mode).

RX_SSI_FSYNC
RX_SSI_CLK
RX_DATA

Earpiece

Audio Jack

ABACUS III

Patriot SAP / BBP

Patriot SPIB

MAKO_CS
SPI_MISOB

SPI_MOSIB
SCKB

Internal Speaker

3

Filter = 22kHz,

Audio Switch

3

CODEC_RX
CODEC_FSYNC
CODEC_DCLK

4

HP & LP

200 Hz

PA_IN_P

LPF = 3.4 kHz

VC_OUT_P

VC_OUT_M

PA_IN_M

Digital

PA Control

CODEC

16-Bit

D/A

Preamp =
0 to 10 dB

G4

G5

EXT PA

G6

INT PA

MAKO IC

G1 Digital Gain

= 0 or 1 dB

Attenuator

= -52 to 0 dB

G3

Figure 3-11. VOCON Receive Audio Path

6871620L01-C May 28, 2008

3-28 Theory of Operation: VOCON Section

3.2.6 Radio Power-Up/Power-Down Sequence

The radio power up sequence begins with pressing the Power On button on the keypad. When the
button is pressed, the mechanical switch MECH_SW pin will be pulled low. If "MECH_SW = "0", and
BAT_7V5 pin is above the "Power Up Threshold", then MAKO IC will pull the FET_ENX pin to
GROUND, thus driving the gate of external P-MOSFET to low, enabling the P-MOSFETs (Q1301
and Q1302) to supply power to the MAKO IC as well as the RF transceiver section (UNSW_B+
supplies B+ to the VOCON section, SW_B+ and RF transceiver section, RFSW_B+).

With SW_B+ enabled, the VSW1 switched regulator will be ready and subsequently, other MAKO
regulators such as V1.875, V1.55, V2 and VCC5 are sequentially enabled and provide power to all
MAKO internal blocks and external systems including the microprocessor (Patriot), memory ICs and
radio RF circuits. The RESETX pin is asserted low for an additional 32ms once all DC regulators are
stable. It is then de-asserted, allowing the microprocessor to start.

In order to power-down the radio, the ON/OFF button has to be pressed for a specified
(programmable) duration (default setting set to 3 seconds). The ON/OFF circuitry will then pull
MECH_SW to high (MECH_SW = 1) and the MAKO IC starts an internal 125ms watchdog timer and
sets the shutdown interrupt flag which causes the INT_X interrupt output pin to assert low. The
microprocessor then determines (via SPI register access) that it must initiate the power-down
sequence. The watchdog timer will be refresh by the microprocessor via SPI to prevent it from timing
out. Upon expiration of the watch dog timer, MAKO will assert RESETX to turn-off all DC regulators
and de-asserts the FET_ENX pin which removes the SW_B+ and RFSW_B+ supplies, thus killing all
power to the radio.

Figure 3-12 and Table 3-5 show the radio ON/OFF circuitry and the radio ON/OFF operation truth

table. The truth table shown is based on a 3 second long press duration for radio power-off criteria.

V2_FIL

ON_OFF_det

R9922

1K

Patriot_ONOFF

R2

Q9906

5V_Misc

5V_Misc

8

U9903

4

D Flip-flop

VCC

GND

C9951

0.10uF

Q

Q‘

MECH_SW

5

3

C9969

0.10uF

ON_OFF

R1

R9924

10K

10K

0.10uF

R9923

5V_Misc

C9953

0.10uF

Inverter

VCC

2

R9925

10K

4

1

GND

3

U9901

R9926

1K

Q9905

5V_Misc

5

1

INB

2

INA

GPIO

C9980

0.10uF

ON/OFF Circuitry

VCC

GND

3

AND Gate

OUTY

U9902

C9952

0.10uF

4

R9927

30K

OR Gate

1

2

4

U9918-1

5V_Misc

U9918-2

PWR_GND

5

VCC

GND

3

R9960

0

7

6

C9954

0.10uF

PR

2

D

1

CP

CLR

Figure 3-12. Radio ON/OFF Circuitry

May 28, 2008 6871620L01-C

Theory of Operation: Encryption Module 3-29

Table 3-5. ON/OFF Operation Truth Table

Condition

Initial State00100000

Press ON11111011

Press<3 Sec11000001

Press=3 Sec11000110

Press>3 Sec11111110

INVERTER
O/P (Pin 4)

AND GATE
INB (Pin 1)

AND GATE

INB (Pin 2)

AND GATE

O/P (Pin 4)

OR GATE

(Pin 1)

OR GATE

(Pin 2)

OR GATE

(Pin 4)

Mech

SW

3.3 Encryption Module

The encryption module connects directly to the VOCON section and interfaces directly with the
vocoder digital circuitry. It contains an independent microcontroller to perform digital, numerical,
encryption algorithms.

The encryption module is designed to digitally encrypt and decrypt voice and ASTRO data in ASTRO
XTS 4000 radios.

NOTE: The encryption modules are NOT serviceable. The information contained in this section is

only intended to help determine whether a problem is due to a encryption module or the radio
itself.

The encryption module uses a custom encryption IC and an encryption key variable to perform its
encode/decode function. The encryption key variable is loaded into the encryption module, via the
radio's CE connector, from a hand-held, key variable loader (KVL). The encryption IC corresponds to
the particular encryption algorithm purchased. Table 3-6 lists the encryption algorithms and their
corresponding kit numbers.

Table 3-6. Encryption Module Software Kits and Algorithms

Software

Kit Number

NNTN7056 ADP, AES

NNTN7057 ADP, DES-XL, OFB

NNTN7058 ADP, DVP-XL

Algorithm

The encryption module operates from two power supplies (UNSW_B+ and SW_B+). The SW_B+ is
turned on and off by the radio's On/Off switch. The UNSW_B+ provides power to the encryption
module as long as the radio battery is in place.

Key variables are loaded into the encryption module. Depending on the type of encryption module,
up to 16 keys can be stored in the module at a time. The key can be infinite key retention or
30-seconds key retention, depending on how the codeplug is set up.

The radio' s host processor communicates with the encryption module on the Synchronous Serial
Interface (SSI) bus. The SSI bus consists of five signal lines. A communication failure between the
host processor and the secure module will be indicated as an ERROR 09/10 message on the
display.

To troubleshoot the encryption module, refer to the flowcharts in Chapter 5 “Troubleshooting Charts.”

6871620L01-C May 28, 2008

3-30 Theory of Operation

Notes

May 28, 2008 6871620L01-C

Troubleshooting Procedures: Handling Precautions 4-1

Chapter 4 Troubleshooting Procedures

The purpose of this chapter is to aid in troubleshooting problems with the ASTRO XTS 4000 radio. It
is intended to be detailed enough to localize the malfunctioning circuit and isolate the defective
component. It also contains a listing of service tools recommended for PC board repair at the
component level.

Most of the ICs are static sensitive devices. Do not attempt to

!

C a u t i o n

4.1 Handling Precautions

Complementary metal-oxide semiconductor (CMOS) devices, and other high-technology devices,
are used in this family of radios. While the attributes of these devices are many, their characteristics
make them susceptible to damage by electrostatic discharge (ESD) or high-voltage charges.
Damage can be latent, resulting in failures occurring weeks or months later. Therefore, special
precautions must be taken to prevent device damage during disassembly, troubleshooting, and
repair. Handling precautions are mandatory for this radio, and are especially important in low­humidity conditions. DO NOT attempt to disassemble the radio without observing the following
handling precautions.

disassemble the radio or troubleshoot a board without first
referring to the following Handling Precautions section.

1. Eliminate static generators (plastics, Styrofoam, etc.) in the work area.

2. Remove nylon or double-knit polyester jackets, roll up long sleeves, and remove or tie back
loose-hanging neckties.

3. Store and transport all static-sensitive devices in ESD-protective containers.

4. Disconnect all power from the unit before ESD-sensitive components are removed or inserted
unless otherwise noted.

5. Use a static-safeguarded workstation, which can be accomplished through the use of an
anti-static kit. This kit includes a wrist strap, two GROUND cords, a static-control table mat
and a static-control floor mat.

6871620L01-C May 28, 2008

4-2 Troubleshooting Procedures: Recommended Service Tools

4.2 Recommended Service Tools

Table 4-1 lists recommended service tools that can be used for PC board repairs at the component

level. For listings of additional service tools, service aids, and test equipment that are recommended
for all levels of service, refer to the XTS 4000 Basic Service Manual (see “ Related Publications” on

page x).

Table 4-1. Recommended Service Tools

Motorola

Part Number

RLN4062 Hot-air workstation, 120V Tool for hot-air soldering/desoldering of

0180302E51 Master lens system

6684253C72 Straight prober

6680384A98 Brush

0180303E45 SMD tool kit (included with

R1319A)

R1319 ChipMaster (110 V) Surface-mount removal and assembly of

R1321 ChipMaster (220 V)

6680309B53 Rework equipment catalog Contains application notes, procedures,

0182297T15 XTS 4000 Keyload Cable Used to load encryption key into radio.

NKN1027 RS232 Cable Kit Connects radio to RLN-4460 Portable Test

Description Application

surface-mounted integrated circuits

surface-mounted integrated circuits and/or
rework station shields. Includes 5 nozzles.

and technical references used to rework
equipment

Connects to radio's CE connector and
key-variable loader (KVL).

Set for radio performance checks, and to
serial port on personal computer for CPS
programming and tuner alignments.

NKN1029 USB Cable Kit Connects radio to RLN-4460 Portable Test

Set for radio performance checks, and to
Universal Serial Bus (USB) port on
personal computer for CPS programming
and tuner alignments.

NNTN7151 Housing Eliminator Fixture that allows radio’s internal board to

be mounted externally. Provides easy
access to electronic circuits, required for
board-level troubleshooting.

NNTN7152 Regulated Battery Eliminator,

XTS 4000

NNTN7153 SMA Conversion RF Adapter Adapts radio’s antenna port to RF cabling

May 28, 2008 6871620L01-C

Used in place of battery to connect radio
to an external power supply.

of test equipment.

Troubleshooting Procedures: Voltage Measurement and Signal Tracing 4-3

Table 4-1. Recommended Service Tools (Continued)

Motorola

Part Number

RLN4460 Portable Test Set Used for radio performance checks.

RVN4181 Customer Programming Software

(CPS) and Tuner Software

NOTE Parts U1401 and U1304 are not field repairable. For failures relating to U1401

and U1304, the mainboard has to be replaced.

Description Application

Connects to radio’s CE connector and
allows remote switching and signal
injection/outputs for test equipment
measurements.

CPS allows customer-specific
programming of modes and features.
Tuner software required to perform
alignment of radio parameters. Can be
used for XTS 5000, XTS 4000 and
XTS 2500 products.

4.3 Voltage Measurement and Signal Tracing

It is always a good idea to check the battery voltage under load. This can be done by checking the
OPT_B+_VPP pin at the radio CE connector (pin 3). The battery voltage should remain at or above

7.0 Vdc. If the battery voltage is less than 7.0 Vdc, then it should be recharged or replaced as
necessary prior to analyzing the radio.

In most instances, the problem circuit may be identified using a multimeter, an RF millivoltmeter,
oscilloscope (preferably with 100 MHz bandwidth or more), and a spectrum analyzer.

When checking a transistor or module, either in or out of

!

C a u t i o n

circuit, do not use an ohmmeter having more than 1.5 Vdc
appearing across test leads or use an ohms scale of less than
x100.

6871620L01-C May 28, 2008

4-4 Troubleshooting Procedures: Standard Bias Table

4.4 Standard Bias Table

Table 4-2 outlines some standard supply voltages and system clocks which should be present under

normal operation. These should be checked as a first step to any troubleshooting procedure.

Table 4-2. Standard Operating Bias

Signal Name Nominal Value Toleran ce VOCON Board Source

24.576 MHz 24.576 MHz ±1000 ppm C1317

32.768 kHz 32.768 kHz ±400 ppm C1303

GATED_32_kHz 32.768 kHz ±400 ppm C1301

CKIH 16.8 MHz C1402

X_16.8 MHz 16.8 MHz R1418

POR 3.0 Vdc ±5% R1121

RESET_OUT 3.0 Vdc ±5% R1105

VSW1 3.85 Vdc ±5% R1319

RAWB+ 7.5 Vdc 6.0-9.0 Vdc C20

V2 2.9 Vdc ±5% C1324

BAT_7V5 7.5 Vdc 6.0-9.0 Vdc R1309

UNSW_B+ 7.5 Vdc 6.0-9.0 Vdc C1129

SW_B+ 7.5 Vdc 6.0-9.0 Vdc C1343

VCC5 5.0 Vdc ±5% C1319

V1.55 1.55 Vdc ±5% C1328

May 28, 2008 6871620L01-C

Troubleshooting Procedures: Power-Up Self-Check Errors 4-5

4.5 Power-Up Self-Check Errors

Each time the radio is turned on, the MCU and DSP perform a series of internal diagnostics. These
diagnostics consist of checking such programmable devices as the FLASH ROMs, and SRAM
devices.

Problems detected during the power-up self-check routines are presented as error codes on the
radio’s display. For non-display radios, the problem is presented at power up by a single, low­frequency tone. Table 4-3 lists possible error codes, a description of each error code, and a
recommended corrective action.

Table 4-3. Power-Up Self-Check Error Codes

Error
Code

01/02 FLASH ROM codeplug Checksum Non-Fatal Error Reprogram the codeplug

01/12 Security Partition Checksum Non-Fatal Error Send radio to depot

01/20 ABACUS Tune Failure Non-Fatal Error Turn radio off, then on

01/22 Tuning Codeplug Checksum Non-Fatal Error Send radio to depot

01/81 Host ROM Checksum Fatal Error Send radio to depot

01/82 FLASH ROM Codeplug Checksum Fatal Error Reprogram the codeplug

01/88 External RAM Fatal Error — Note: Not a checksum error Send radio to depot

01/90 General Hardware Failure Fatal Error Turn radio off, then on

01/92 Security Partition Checksum Fatal Error Send radio to depot

01/93 FLASHport Authentication Code Failure Send radio to depot

01/98 Internal RAM Fail Fatal Error Send radio to depot

01/A2 Tuning Codeplug Checksum Fatal Error Send radio to depot

02/81 DSP ROM Checksum Fatal Error Send radio to depot

02/88 DSP RAM Fatal Error — Note: Not a checksum error Turn radio off, then on

Description Corrective Action

02/90 General DSP Hardware Failure (DSP startup message not

received correctly)

09/10 Secure Hardware Failure Turn radio off, then on

09/90 Secure Hardware Fatal Error Turn radio off, then on

6871620L01-C May 28, 2008

Turn radio off, then on

4-6 Troubleshooting Procedures: Power-Up Self-Check Diagnostics and Repair (Not for Field Use)

4.6 Power-Up Self-Check Diagnostics and Repair (Not for Field Use)

Table 4-4 lists additional action items that can be used for the diagnosis and resolution of the error

codes listed in Table 4-3 on page 4-5.

Table 4-4. Power-Up Self-Check Diagnostic Actions

Error
Code

01/02 This non-fatal error will likely recover if the radio's power is cycled. In the event that this

does not resolve the issue, the radio should be reflashed. As a last resort, the FLASH
ROM U1410 should be replaced.

01/12 The radio should be sent to the depot for reflashing of the security codeplug.

01/20 Cycling radio power should resolve this issue.

01/22 The radio should be sent to the depot for reflash of the tuning codeplug followed by

retuning of the radio.

01/81 The radio should be sent to the depot for reflashing of the host code.

01/82 The radio should be sent to the depot for reflashing of the radio codeplug.

01/88 Reflashing of the radio should first be performed. If this fails to resolve the issue, then

replacement of the SRAM U1409 is necessary.

01/90 Cycle power to radio. Continued failure indicates a likely IC failure (MAKO, PCIC,

ABACUS). In this event, radio should be sent to the depot for isolation and repair of the
problem IC.

01/92 The radio should be sent to the depot for reprogramming of the security codeplug.

01/93 The radio should be sent to the depot for reflashing of the host code.

01/98 Send radio to the depot for replacement of the SRAM U1409.

Diagnostic Actions

01/A2 The radio should be sent to the depot for reflashing of the tuning codeplug followed by

re-tuning of the radio.

02/81 The radio should be sent to the depot for examination and/or replacement of either the

FLASH U1410, or the PATRIOT MCU/DSP U1401.

02/88 Cycle power to the radio. If this does not fix the problem, then the radio should be sent

to the depot for reflashing of the DSP code. Continued failure requires examination and/
or replacement of the SRAM U1409.

02/90 Cycle power to the radio. If this fails to fix the problem, then the radio should be sent to

the depot for reflashing of the DSP code. Continued failure may require replacement of
U1401, the PATRIOT MCU/DSP.

09/10 Cycle power to the radio. If this fails then follow instructions in the secure hardware

failure troubleshooting flowchart.

09/90 Cycle power to the radio. If this fails then follow instructions in the secure hardware

failure troubleshooting flowchart.

May 28, 2008 6871620L01-C

Troubleshooting Charts: List of Troubleshooting Charts 5-1

Chapter 5 Troubleshooting Charts

This section contains detailed troubleshooting flowcharts. These charts should be used as a guide in
determining the problem areas. They are not a substitute for knowledge of circuit operation and
astute troubleshooting techniques. It is advisable to refer to the related detailed circuit descriptions in
the theory of operation sections prior to troubleshooting a radio.

5.1 List of Troubleshooting Charts

Most troubleshooting charts (see Table 5-1) end up by pointing to an IC to replace. It is not always
noted, but it is good practice to verify supplies and GROUNDs to the affected IC and to trace
continuity to the malfunctioning signal and related circuitry before replacing any IC. For

instance, if a clock signal is not available at a destination, continuity from the source IC should be
checked before replacing the source IC.

Table 5-1. Troubleshooting Charts List

Chart Title Page No.

Main Troubleshooting Flowchart 5-2

Power-Up Failure 5-3

DC Supply Failure 5-6

Display Failure 5-10

Volume Set Error 5-13

Button Test 5-14

Top/Side Button Test 5-15

VCO TX/RX Unlock 5-16

VOCON TX Audio 5-17

VOCON RX Audio 5-19

RX RF

TX RF 5-26

Keyload Failure 5-29

Secure Hardware Failure 5-30

5-21

6871620L01-C May 28, 2008

5-2 Troubleshooting Charts: Main Troubleshooting Flowchart

5.2 Main Troubleshooting Flowchart

Start

Go to

TX RF

flowchart

Go to

TX RF

flowchart

Go to

VOCON

RX Audio

flowchart

No

No

No

Good

power-up

Self-Test?

Yes

Is there

TX Power?

Yes

Is TX

Deviation

OK?

Yes

Receive

Audio?

No

Error

Message?

Yes

See Table 4-3:
Power-up Self-

Check Error

Codes

No

Go to either
Display Failure or
Power-Up Failure

flowchart

Yes

No

See Button

Test flowchart

May 28, 2008 6871620L01-C

No

Good

SINAD?

Yes

Buttons

Functional?

Yes

End

Troubleshooting Charts: Power-Up Failure 5-3

5.3 Power-Up Failure–Page 1

Radio

Power-Up

Failure

Verify Standard

Bias in

Table 4-2

Isolate and
Repair Problem
See DC Supply

Failure flowchart

No

Standard

Bias OK?

Signal may appear

for a very short period

of time (50 ms). Use

an oscilloscope with

trigger to capture signal

Yes

Probe

32.768 kHz

Clock at C1303

Signal

Present?

Yes

1

No

Verify intergrity

of C1305 &

C1306

2

6871620L01-C May 28, 2008

5-4 Troubleshooting Charts: Power-Up Failure

Power-Up Failure–Page 2

1

Signal may
appear for a very
short period of

Probe

16.8 MHz

Signal at R1416

time (50ms). Use
an oscilloscope
with trigger to
capture signal

Signal

greater than

1 Vp-p

Yes

Check

16.8 MHz
Signal at

C1402

Signal

greater than

1 Vp-p

Yes

Refer Board to

Service Depot for

Reflash, Patriot,

SRAM, and

FLASH Analysis

No

No

Investigate

16.8 MHz

Reference

Oscillator

This signal may
contain harmonics
and, therefore, may
not appear as a
perfect sinewave

Investigate

Clock Buffer

Components and

Isolate Problem

May 28, 2008 6871620L01-C

Troubleshooting Charts: Power-Up Failure 5-5

Power-Up Failure–Page 3

2

Components

OK ?

Yes

Replace

Y 1301

Fixed?

Yes

No

No

Replace

Problem

Component

Replace

Mainboard

Fixed?

No

Yes

End

6871620L01-C May 28, 2008

5-6 Troubleshooting Charts: DC Supply Failure

5.4 DC Supply Failure–Page 1

NOTE: Since the failure of a critical voltage supply might cause the radio to automatically power

down, supply voltages should first be probed with a multimeter. If all the board voltages
are absent, then the voltage test point should be retested using a rising-edge-triggered
oscilloscope. If the voltage is still absent, then another voltage should be tested using the
oscilloscope. If that voltage is present, then the original voltage supply in question is
defective and requires investigation of associated circuitry.

Problem With

DC Power

Disctribution

Check voltage at

pin 4, U1101

Voltage =

UNSW _B+

Yes

Check voltage at

pin 5, U1101

Voltage =

5 Vdc

Yes

1

No

No

Check continuity of

Fuse F901

Check D4,

VR1209, R1133

C1141

Fuse OK?

Yes

Check battery

connection for

good contact

Components

OK?

Yes

Replace U1101

No

No

Replace Fuse

Replace problem

components

May 28, 2008 6871620L01-C

Troubleshooting Charts: DC Supply Failure 5-7

DC Supply Failure–Page 2

1

Check voltage at pin

1,2,3,6,7 & 8 of Q1302

Voltage =

SWB+

7.5V +/­20% ?

Yes

Check voltage at

R1320

Voltage =

SWB+?

Yes

Check voltage at

C1337

No

No

Check voltage at

R1311

(FET_ENX)

Check L1307,

L1308, R1320,

R1321, C1342 &

C1343

Voltage =

GND?

Yes

Component

= OK?

No

No

Replace Mainboard

Replace Q1302

Replace problem

components

Voltage =

?

Yes

2

No

Replace Mainboard

6871620L01-C May 28, 2008

5-8 Troubleshooting Charts: DC Supply Failure

DC Supply Failure–Page 3

2

Check voltage at

R1319

,

, V2

No

No

No

Check L1306 &

C1333

Check L1304,
C1330 & C1331

Check L1303,

C1328 & C1329

3

Voltage =

3.8 Vdc +/ ­5%?

Yes No

Check voltage

at L130 4

Voltage =

1.875 Vdc
+/- 5%?

Yes

Check voltage at

L1303

Voltage =

1.55 Vdc
+/- 5%?

Yes

Check voltage

at L1302

Component

OK?

Replace problem

components

Component

OK?

Yes

ReFLASH HOST

C Code

Component

OK?

Yes

3

Yes

No

No

Check R1318

Component
OK?

Replace problem

components

Fixed ?

Replace problem

components

Yes

3

No

No

Yes

Replace problem

components

END

Replace Mainboard

Voltage =

2.9 Vdc +/ ­5%?

Yes

Check voltage at

L1301

Voltage =

5.0 Vdc +/ ­5%?

Yes

4

No

No

Check L1302,

C1324 & C1325

Check L1301,

C1318, C1319 &

VR1206

Component

OK?

Yes

3

Component

OK?

YES

3

No

No

Replace problem

components

Replace problem

components

May 28, 2008 6871620L01-C

Troubleshooting Charts: DC Supply Failure 5-9

DC Supply Failure–Page 4

4

Check voltage at

Check voltage at

C14

Voltage =

5.0 Vdc +/ ­5%?

Yes

C27

Voltage =

3.0 Vdc +/­5%?

No

No

Check Q4, E5, D1,

C10, C11, C12,

C14, Q1301 &

R1709

Check L10, D3,
C25, C26, C27,

C28 & C30

Component

OK?

Yes

Replace U1

Component

OK?

No

No

Replace problem

components

Replace problem

components

Yes

Check voltage at

C17

Voltage =

3.0 Vdc +/­5%?

Yes

END

No

Check D2, C15,

C16, C17 & C9

Yes

OK?

Yes

No

Replace problem

components

Replace U3

Component

Replace U2

6871620L01-C May 28, 2008

5-10 Troubleshooting Charts: Display Failure

5.5 Display Failure–Page 1

No Display

(Main or/and

CID Display)

Test Display operation with

a known working

Front Flip Assembly

(with Working Display Module)

Problem

Resolved?

No

Check DC

on J1 pin 24

& pin 54

-2.775 V< pin 24 <3.1 V?

-1.8 V< pin54 <1.96 V?

No

Check integrity of

E1102 & E1103

E1102 OK?
E1103 OK?

Yes

Replace defective Display Module

in Front-Flip Assembly

Yes

No

1

Replace

E1102 or E1103

Yes

Verify V2 or V1.875

using

DC Supply Failure

flowchart

May 28, 2008 6871620L01-C

Troubleshooting Charts: Display Failure 5-11

Display Failure–Page 2

1

Check DC at

J1-25, J1-37,

J1-42 & J1-44

J1-25 = 0V?
J1-37 = 1.875V?
J1-42 = 1.875V?

J1-44 = 0C?

Yes

Check RESET

at J1, pin 33

V = 2.9V

+/- 20%?*

Yes

Probe signals at

J1-19, J1-23,

J1-39, J1-58

& J1-60

Any Digital data

or activity?

Yes

No Yes

* per Standard Bias Table

No Yes

Verify Signal

Path Integrity

and correct

Verify Signal
Path Integrity

and correct

Verify Signal

Path Integrity

and correct

Problem

Resolved?

No

Problem

Resolved?

No

Problem

Resolved?

No

End

YesNo

End

End

Probe Display Date Lines
(J1-13, J1-15, J1-27, J1-29,
J1-35, J1-36, J1-38, J1-40,
J1-45, J1-47, J1-49, J1-51,

J1-53, J1-55, J1-57 & J1-59)

Any Digital data

or activity?

Yes

3

No

Verify Signal

Path Integrity

and correct

Problem

Resolved?

No

Yes

End

6871620L01-C May 28, 2008

5-12 Troubleshooting Charts: Display Failure

Display Failure–Page 3

3

Use an oscilloscope to check for
a low-level (0V) pulse occurrence
during power-on initialization period.

Check Active

Low Status on

RESET (J1-33)

Low-

Level Pulses

Present?

Yes

Check 60-pin Display

and Keypad Flex.

Replace if neccessary

No

Replace Mainboard

May 28, 2008 6871620L01-C

Troubleshooting Charts: Volume Set Error 5-13

5.6 Volume Set Error

Volume

Set Error

Synopsis

Verify operation

of volume

Buttom Test

flow chart

This chart relates to failure in the volume

button. Basic failure modes are as follows:

1) Bad connection

2) Defective volume control button

3) Detective MAKO IC U1304

4) Problem in receive audio circuit

Refer to “No

Receive Audio”

flow chart

Any Digital data

or activity?

Yes

Volume

button OK?

Using a voltmeter,

measure voltage at

C1106. The value

should be V2

Volume control

No

Replace

button flex

Voltage

Functional?

Replace Mainboard

to Top and Side

Control Flex J(3)

No

Volume

pot OK?

Yes

Yes

No

Replace

Mainboard

Verify contact

with circuit

board

6871620L01-C May 28, 2008

5-14 Troubleshooting Charts: Button Test

5.7 Button Test

End

Button Test

Place radio in Test Mode.
Press Clear/Secure Button
so display reads CH TEST.
This places the radio in
Button Test Mode.
Then, press the orange
(Emergency) Button to
verify codes displayed
as shown in the Button
Table at right

Yes

Ke y s

correct?

No

Check signal

path integrity of

button in question

Synopsis

This chat relates to a failure in the button functions.
Basic Failure modes are as follows:

1) Failure in Keypad Flex & Connectors within the
Front Flip Assembly

2) Failure in Top Control Flex & Connectors within the
Radio Chassis Assembly

3) Bad connections

4) Defective Patriot IC

Button Table
Button
PTT

Emergency Button
Clear/ Secure Button

Volume Up Button
Volume Down Button
Programmable Button

131/0-1

131/0-1

97/0-1

97/0-1

129/0-1 134/0-1

129/0-1 134/0-1

128/0-1

128/0-1

132/0-1 133/0-1

132/0-1 133/0-1

135/0-1

135/0-1

Code
1/ 0-1

3/ 0-1
96/ 0-1
80/ 0-1
81/ 0-1
98/ 0-1

130/0-1

130/0-1

ON/OFF

ON/OFF

* Note: The Button Test applies to all buttons
on the radio EXCEPT the ON/OFF button
on the keypad. This button solely serves
radio Power-Up/ Power-Down functionality.

136/0-1

136/0-1

49/0-1 50/0-1 51/0-1

49/0-1 50/0-1 51/0-1

1 .,? 2ABC 3DEF

1 .,? 2ABC2ABC 3DEF3DEF

52/0-1 53/0-1 54/0-1

52/0-1 53/0-1 54/0-1

4GHI 5JKL 6M NO

4GHI4GHI 5JKL5JKL 6M NO6MNO

55/0-1 56/0-1 57/0-1

55/0-1 56/0-1 57/0-1

7PRS 8TUV 9XYZ

7PRS 8TUV8TUV 9XYZ9XYZ

58/0-1 48/0-1 59/0-1

58/0-1 48/0-1 59/0-1

0 #

*

**

00 ##

May 28, 2008 6871620L01-C

Troubleshooting Charts: Top/Side Button Test 5-15

5.8 Top/Side Button Test

Top/Side Button

Test

Verify operation

of zone knob

using Button Test

flowchart

This chart relates ro a failure in
reading the buttons: Emergency,
Side Button 1, Side Button 2, or
SIde Button 3.

Basic failure modes are as follows:

1) Failure in controls flex circuit

2) Bad connection

3) Defective Switch

4) Defective A/D port in GCAP II

Synopsis

Replace
U1304

No

Using RSS, verify
problem button is

enabled for

function

Buttons

enabled?

No

Use RSS
to enable

button

Replace U1305

Problem

Fixed?

Yes

Using a voltmeter, measure the
voltage at U1305 pin 3 while

Yes

depressing the following buttons:
Emergency, Side Button 1,
Side Button 2, and Side Button 3.
The probe points are as follows:

Emergency Button 0.03V
Clear/Secure Button 1.40V
Programmable Button 2.20V
No Button Pressed 2.85V

Yes

Yes

Button check

Levels
Correct?

End

OK?

No

No

Verify physical

operation of

buttons

Buttons

OK?

No

Replace Radio
Chassis Assembly

Yes

Verify connections

and Control Top/ PTT

flex circuit and repair

as necessary

6871620L01-C May 28, 2008

5-16 Troubleshooting Charts: VCO TX/RX Unlock

5.9 VCO TX/RX Unlock

VCO TX/RX

unlock

Sniff: Using an inductive field probe

"Sniff"

frequency near

VCO shield

as an antenna to measure

frequency. Place the probe

approximately 1/2 inch away

from components to be sniffed.

Frequency

detected?

Yes

Check control

voltage at

Vctrl TESTPOINT

<0.6Vdc

>11.0Vdc or

drifting?

Yes

Check parts

around U202. If

OK, replace U202

No

OK, replace U3

No

spectrum analyzer

No

VOCON Section

5V at C14?

Yes

Check parts

around U3. If

Check if VCO

is locked using

VCO locked?

Yes

Check

No

No

No

Check parts

around U1. If

OK, replace U1

3V at C27?

Yes

Remove

VCO shield

Is unit

VHF?

Yes

Aux. line 3
high for TX

or low for RX

(VHF)?

No

No

Is unit

UHF?

Yes

Aux. 3

for TX

and aux 2

for RX

(UHF)?

Yes

Is pin 19

of VCOBIC

low for RX and

4.5V for TX?

Yes

Check parts
around U302.
If OK, replace

U302

Check parts

No

around Q310. If

OK, replace Q310

Q253 = 4.5V for RX?

Yes

Is Q273 = 4.5V

for TX and

Yes

Check parts

around Q253 and

Q273.

If OK, replace

Q253 and Q273

May 28, 2008 6871620L01-C

Troubleshooting Charts: VOCON TX Audio 5-17

5.10 VOCON TX Audio–Page 1

Radio has no

Transmitter Deviation

(VOCON Evaluation)

Inspect UCM-CE-Audiojack

Flex and Flex Connectors
(from Front Flip Assembly

to Mainboard)

Connections

OK?

Yes

Connect an

RLN4460A audio

test box (or equivalent)

to the radio CE

Connector

Inject a 200 mV

rms 1.0 kHz tone

to the test box

Audio In port

Is FM

deviation approx.

3.0 kHz?

No

No

Yes

Repair connections

and/or replace flex

No Problem

found.

End

Probe at

C1347

Is

1 kHz Signal

present?

Yes

1

No

Verify Integrity

of Mic path up

to C1347

Problem

with Mic path

components?

No

2

Yes

Replace

appropriate

component

6871620L01-C May 28, 2008

5-18 Troubleshooting Charts: VOCON TX Audio

VOCON TX Audio–Page 2

1

Use an oscilloscope to check the
SSI audio signals from the MAKO
(U1304). The following test points
are used for data collection:
CODEC_DCLK (R1335): 512 kHz Square Wave Clock
CODEC_TX (R1337): Audio Data Words
CODEC_FSYNC (R1336): 8 kHz Frame Sync Pulse

Clock

and Frame Sync

present?

Yes

Data

present at

CODEC_TX?

Yes

Go to

TX RF

flowchart

2

Check

UCM-CE-Audiojack

Flex and Flex

Connectors

No

No

Replace

Mainboard

Connections

No

OK?

Yes

Problem

Resolved?

Yes

End

No

Repair connections

and/or

replace flex

Problem
Solved?

No

1

Yes

End

May 28, 2008 6871620L01-C

Troubleshooting Charts: VOCON RX Audio 5-19

5.11 VOCON RX Audio–Page 1

Bad SINAD

Bad 20db Quieting

No Recovered Audio

A standard input is an

Inject Standard

Input into

RF Jack J1704

RF signal with a 1 kHz
tone modulated with 3 kHz
deviation in a 25 kHz channel.

Check Preamp

Output Signal at

C1355*

Signal

Present?

Yes

Check

Distortion of

Signal at C1355

THD <3%?

Yes

1

* Note: The Preamp output signal
should be checked differently
across C1355.

Probe R1338 for

Data, Compare

with RX SAP

waveform, Trace 2

No

Data

Present?

Yes

Replace

Mainboard

Go to

RX RF

flowchart

for Clock Signal,

NoNo

waveform, Trace 3

Probe R1335

Compare with

RX SAP

Present?

Probe R1336 for

Frame Sync Signal,

Compare with

RX SAP waveform,

Trace 1

Yes

Present?

Replace

Mainboard

Clock

Yes

Frame

Sync

No

No

6871620L01-C May 28, 2008

5-20 Troubleshooting Charts: VOCON RX Audio

VOCON RX Audio–Page 2

1

Check Audio PA output

signal at VR1201

pins 1 & 4 (differential)

Check DC level,

V at R1328.

Signal

Present?

Yes

No

If V=7.50 +/- 1V,

then replace U1304.

Otherwise, verify R1328.

Distortion

>3%?

No

Check connector J2.

If no problems were found

on connector J2, check

UCM-CE-Audiojack flex.

Yes

May 28, 2008 6871620L01-C

Troubleshooting Charts: RX RF 5-21

5.12 RX RF–Page 1

Poor RX
sensitivity or
no RX audio

Inject a standard FM test signal into the

RF Jack J1704. Use SMA Conversion

RF Adapter NNTN7153A to inject the

test signal into RF Jack. Use CPS to

ensure that attenuator feature is disabled.

Use a spectrum analyzer and

high-impedance RF probe to

measure the IF signal

VHF: between L472 and L490
UHF: before L490

Frequency OK?

VHF: 44.85 MHz
UHF: 73.35 MHz

Yes

IF

level about

-38 dBm?

No

Measure RF

input level

at J1704 pin 3

No

Yes

3 kHz FM deviation,

1 kHz rate, -47 dBm

Check
RXLO

1

RF level

about

-47 dBm?

Yes

Measure RF levels at C410,

compute SW_FL loss

SW_FL

loss < 2 dB?

Yes

2

No

No

Inspect

RF Jack J1704

SMA Conversion RF Adapter,

Check

SW_FL

Visual

inspection

OK?

Yes

Verify

measure insertion loss

Loss

< 0.2 db?

Yes

Bad RF Jack.

Replace mainboard

(Jack is not

serviceable)

No

No

Replace
bad part

Replace

adapter

6871620L01-C May 28, 2008

5-22 Troubleshooting Charts: RX RF

RX RF–Page 2

1

2nd LO, VHF: 42.6 MHz, UHF: 71.1 MHz

Remove SH04 and measure

2nd LO at C560 on

PCB side 2

about 356 mVpp

2nd LO DC bias

Signal

Present?

Yes

LO Freq.

OK?

VHF: 42.6 MHz
UHF: 71.1 MHz

Yes

Measure

RX_SSI_CLK (R1123)

RX_SSI_FSYNC (R1125)

RX_SSI_DATA (R1124)

Observe

0 to 3 Vdc

digital signals

Levels

OK?

Yes

No

No

No

Q551-c

= 5.0 Vdc?

Yes

Q551-e

3

5

= 3.7 Vdc?

Yes

Remove SH11 and

inspect 2nd LO VCO

Visual

examination

OK?

Yes

Replace

Q550

No

No

No

Check Voltage

Regulator U1

Replace

Q551

Repair

Defects

Measure

bit clock rate (Fbit)

at RX_SSI_CLK

RX_SSI_DATA =

Fbit =

1.2 MHz?

Yes

RX_SSI_FSYNC =

20 kHz sync pulse

RX_SSI_FSYNC

OK?

Yes

No

No

4

5

24-bit I, 24-bit Q,

8-bit AGC. AGC

varies with RF level

RX_SSI_DATA

OK?

Yes

Go to

VOCON RX

AUDIO flowchart

No

5

May 28, 2008 6871620L01-C

Troubleshooting Charts: RX RF 5-23

RX RF–Page 3

2

Measure RF levels at

first preselector filter and

compute filter loss.

I/P C410, O/P L480

Loss < 3 db?

Yes

Measure RF levels at LNA

and compute LNA gain.

VHF: I/P L480, O/P C434
UHF: I/P L480, O/P C436

Gain

about

+12 dB?

Yes

Measure RF levels at

second preselector filter and

compute filter loss.

VHF: I/P C450, O/P C455
UHF: I/P C426, O/P C427

No

No

6

Check

LNA

3

Measure

control voltage

at TP551

Fvco

too low?

VHF: < 42.6 MHz
UHF: < 71.1 MHz

Yes

TP551

= 5 Vdc?

Yes

Remove SH11

inspect second LO VCO

and

Visual

examination

OK?

Yes

TP551

(Vdc)

1.10

3.10

No

No

No

2nd LO
at C560

(MHz)

VHF

42.6

47.1

5

Fvco

= 0 Vdc?

Repair

defects

UHF

71.1

75.6

TP551

Yes

No

5

Loss

< 3 dB?

Yes

Measure RF and IF level at mixer

and compute mixer conversion gain.
VHF: RF I/P C470, IF O/P between

L472 & L490

UHF: RF I/P C470, IF O/P L490

Mixer

gain about

3 dB?

Yes

No

No

8

Check

mixer

Replace

Varactor D550

Measure IF level at XTAL filter

and compute XTAL filter loss.

I/P between L472 & L490,

VHF: O/P C491
UHF: O/P C584

Loss

< 4 dB?

Yes

No problem

found

No

7

6871620L01-C May 28, 2008

5-24 Troubleshooting Charts: RX RF

RX RF–Page 4

Clock

4

synthesizer

5

Measure

tuning voltage

(Vt) at R572

Fbit

< 1.2 MHz?

Yes

Vt= 3 Vdc?

Yes

Repair

defects

No

No

Vt = 0 Vdc?

5

Inspect clock

oscillator circuit at

U500-19, 20

No

examination

Yes

Visual

OK?

No

Inspect
components
surrounding

U500

Visual

5

examination

OK?

Yes

Replace

Abacus

U500

No

Repair

defects

Yes

Replace

Varactor D570

May 28, 2008 6871620L01-C

Troubleshooting Charts: RX RF 5-25

RX RF–Page 5

6

Measure preselector filter

tuning voltage dac2 at

VHF: C413
UHF: C420

Tune the radio across several

channels. Measure dac2,

proportional to frequency.

Dac

voltages

OK?

Yes

Check discrete

preselector filters.

No

8

Replace

PCIC

7

Check IF filter and

LC matching networks.

Visual

inspection

OK?

Yes

Replace IF filter.

VHF/ UHF: FL490

Band F (MHz) dac2 (Vdc)

VHF

UHF

136
174

380
470

No

0.9

2.1

0.9

3.1

Repair

defects

6871620L01-C May 28, 2008

5-26 Troubleshooting Charts: TX RF

5.13 TX RF–Page 1

No or low
TX power

Measure RF Power at

Use a spectrum analyzer

and high-impedance RF

probe. Measure TXRF

at C101

RF Jack J1704

(via a Power Meter)

Frequency

OK?

Yes

Level
about

3 dBm?

Yes

Measure RF level

at Q107 pin 1

Level about

+20 dBm?

No

No

No

1

Check

FGU

Check

FGU

Power 2W?

Yes

END

No

2

Yes

May 28, 2008 6871620L01-C

Troubleshooting Charts: TX RF 5-27

TX RF–Page 2

1

Measure

DC Level

at U102-6

7.2 Vdc?

Yes

Measure

DC Level at

U102-14

7.2 Vdc?

No

No

Check

continuity

Check

continuity

2

Measure

RAWB+

at Q107-drain

RAWB+

about

7.2 Vdc?

Yes

Measure gate bias

at C127

V.gate

VHF: about 3 to

4 Vdc?

UHF: 3 Vdc?

No

No

Check

continuity

Check

continuity

Yes

Measure

Vgate at TP111,

normally 4 to

5 Vdc

Vgate

> 4 Vdc?

Yes

DC bias is OK,

control is OK,

RFIN is OK, driver

has low gain

Check parts under SH06.

If all parts are OK,

replace U102.

No

Yes

DC bias is OK,

control is OK,

RFIN is OK,

PA has low gain

Measure RF

3

level at

pin 6 of Q107

Level

about

+35 dBm?

Yes

Remove SH08

and check for

parts off pad

No

Replace

Q107

6871620L01-C May 28, 2008

5-28 Troubleshooting Charts: TX RF

TX RF–Page 3

3

Vgate at TP111

is low (< 4 Vdc)

Measure INT

at TP104

INT > 5 Vdc?

No

INT is low.

Measure VLIM at

PCIC U104 pin 19

VLIM

about 2 to

3 Vdc?

Yes

PCIC is

programmed.

Measure TEMP

at R135

TEMP

< 1.0 Vdc at

25C?

Yes

No

No

Replace

Q101

Bad PCIC

Replace U104

Repair temperature

sensor circuit

(U103 & R135)

Yes

Measure

RFIN at

C128

Low output power,

RFIN is high, check

Secoondary Cutback

circuit (Q102, RT150,

R120, R121, R122).

Repair defects.

< 0.5 Vdc?

Yes

RFIN is low, INT

is low, bad PCIC,

replace U104

No

May 28, 2008 6871620L01-C

Troubleshooting Charts: Keyload Failure 5-29

5.14 Keyload Failure

Keyload Failure

Verify the use of the correct secure kit and key loader:
XTS 4000 UCM Kits:

Software Kits:
NNTN7056 - ADP, AES
NNTN7057 - ADP, DES-XL, OFB
NNTN7058 - ADP, DVP-XL

Use KVL - 3000 or later model Keyloader. Use with
cable 0182297T15.

Obtain correct

KVL and

cable

No

Correct

equipment?

Yes

With KVL attached to

radio and radio on,

verify display

message "KEYLOAD"

This failure relates to secure­equipped radios and indicates a
failure to load key with the KVL
indicated by the message
"KEYFAIL" and key-fail tone.
Typical failure modes would be:

1) Open between UCM-CE-Audiojack
which places radio in Keyload mode.

2) Use of wrong KVL or KVL cable
for XTS 4000 radio.

3) Failure of secure module.

Synopsis

Verify and repair

connection of CE_CTS,

CE_RS232DIN_USB-,

and CE_OPT_SEL2 signals

from KVL to connector J2

Good

connection?

Replace

Mainboard

Yes

No

"KEYLOAD"

message

displayed?

Verify connection

of testpoint

LHDATA_KEYFAIL

No

to R1354

Repair

connection

Yes

With KVL attached to radio

and radio on, initiate a keyload

by pressing PTT on the

keyloader and look for activity

on testpoint LHDATA_KEYFAIL

No

Activity?

Repair

connection

Yes

Verify connection

UCM-CE-Audio

No

connection?

across the

Jack flex

Good

Yes

Replace

secure

module

6871620L01-C May 28, 2008

5-30 Troubleshooting Charts: Secure Hardware Failure

5.15 Secure Hardware Failure

Fail

09/10 or 09/90

Secure Hardware

Failure

Synopsis

This failure relates to secure-equipped
radios and indicates a power-up self-test failure
for the secure module. More specifically this
failure indicates a failure in communications
between the DSP and secure module. The
secure module is not considered field repairable
so troubleshooting is limited to verifying a
problem with the module and replacing.
Typical failure modes would be:

1) Open between secure module and VOCON
section at connector J2.

2) Failure of the SSI bus that the DSP uses to
communicate with the secure module.

3) Failure to get proper supplies and grounds
to J2.

Repair

opens

Replace module

with known good

one and retest

Verify connections

to secure module

No

Yes

Connections

known good

through J2

good?

Yes

Is

module

available?

Radio

functions with

known good

module?

Yes

Replace

secure

module

No

Use ohmmeter to electrically

No

verify the following signal
connections to source IC:
Signal @ J2 Source
ENC_SSI_DI R1338
ENC_SSI_DO R1337
ENC_SSI_CLK R1335
RESET_ENC R1406

Verify bias of following signals:
Signal @ J701 Nominal Bias

FU_B+ 7.5VDC+/-1.0VDC
SW_B+ 7.5VDC+/-1.0VDC
GND GND

Replace

Mainboard

Connections

good?

Yes

Verify electrical activity
at the following signals
at power up:
Signal @ J701 Source
ENC_SSI_DI R1338
ENC_SSI_CLK R1335

No

Signals

good?

No

Yes

Repair

connections

Replace

secure

module

May 28, 2008 6871620L01-C

Troubleshooting Waveforms: List of Waveforms 6-1

Chapter 6 Troubleshooting Waveforms

This chapter contains images of waveforms that might be useful in verifying operation of certain parts
of the circuitry. These waveforms are for reference only; the actual data depicted will vary depending
on operating conditions.

6.1 List of Waveforms

Table 6-1 lists each waveform and the page on which the waveform can be found.

Table 6-1. List of Waveforms

Waveform Page No.

24.576 MHz Clock 6-2

16.8 MHz Buffer Input and Output 6-3

32.768 kHz Clock Outputs 6-4

Receive Serial Audio Port (SAP) 6-5

Receive Baseband Interface Port (RX BBP) 6-6

Transmit Baseband Interface Port (TX BBP) 6-7

6871620L01-C May 28, 2008

6-2 Troubleshooting Waveforms: 24.576 MHz Clock

6.2 24.576 MHz Clock

24.576 MHz clock from Y1302.
Trace 1 (Channel 2): Trace recorded at C1317.

Figure 6-1. 24.576 MHz Clock Waveform

May 28, 2008 6871620L01-C

Troubleshooting Waveforms: 16.8 MHz Buffer Input and Output 6-3

6.3 16.8 MHz Buffer Input and Output

Trace 1 (Channel 2): Buffer input at R1416.
Trace 2 (Channel 3): Buffer output at C1402.

Figure 6-2. 16.8 MHz Buffer Input and Output Waveforms

6871620L01-C May 28, 2008

6-4 Troubleshooting Waveforms: 32.768 kHz Clock Outputs

6.4 32.768 kHz Clock Outputs

Trace 1 (Channel 2): Output at C1303 (from Y1301).
Trace 2 (Channel 3): Output at C1301 (to Patriot IC CKIL input).

Figure 6-3. 32.768 kHz Clock Outputs Waveforms

May 28, 2008 6871620L01-C

Troubleshooting Waveforms: Receive Serial Audio Port (SAP) 6-5

6.5 Receive Serial Audio Port (SAP)

MAEPF-27494-O

Trace 1: 8 kHz frame sync at R1336 (each word is 13 bits after failing edge of FSYNC).
Trace 2: SAP data at R1338 (audio data from MAKO IC CODEC to Patriot IC DSP).
Note: Transmit is identical, except data acquired at R1337.
Trace 3: 512 kHz bit clock at R1335.

Figure 6-4. Receive Serial Audio Port (SAP) Waveforms

6871620L01-C May 28, 2008

6-6 Troubleshooting Waveforms: Receive Baseband Interface Port (RX BBP)

6.6 Receive Baseband Interface Port (RX BBP)

Trace 1: BBP RX frame sync signal at R1111.
Trace 2: BBP RX clock signal at R1109.
Trace 3: BBP RX data signal at R1110.

Figure 6-5. Receive Baseband Interface Port (RX BBP) Waveforms

May 28, 2008 6871620L01-C

Troubleshooting Waveforms: Transmit Baseband Interface Port (TX BBP) 6-7

6.7 Transmit Baseband Interface Port (TX BBP)

Trace 1: BBP TX frame sync signal at R1114.
Trace 2: BBP TX clock signal at R1112.
Trace 3: BBP TX data signal at R1113.

Figure 6-6. Transmit Baseband Interface Port (TX BBP) Waveforms

6871620L01-C May 28, 2008

6-8 Troubleshooting Waveforms

Notes

May 28, 2008 6871620L01-C