Motorola EP350 Service Manual
EP350
Portable Radios
Detailed Service Manual
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Manual No.: 6878422A01
COPYRIGHT
Copyrights
© 2009 by Motorola, Inc. All rights reserved.
No part of this manual may be reproduced, transmitted, stored in a retrieval system, or translated into
any language or computer language, in any form or by any means, without the prior written
permission of Motorola Inc.
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 royalty-free license to use that arises by operation of law in the sale of a
product.
i
Trademarks
MOTOROLA and the Stylized M Logo are registered in the U.S.Patent and Trademark Office. All
other product or service names are the property of their respective owners.
ii
SAFETY INFORMATION
Product Safety and RF Energy Exposure Compliance
These servicing instructions are for use by qualified personnel only. To
reduce the risk of electric shock, do not perform any servicing other than that
contained in the Operating Instructions unless you are qualified to do so.
Refer all servicing to qualified service personnel.
Before using this product, read the operating instructions for safe usage
contained in the Product Safety and RF Exposure booklet enclosed with your
radio.
ATTENTION!
This is restricted to occupational use only to satisfy ICNIRP 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
(Motorola Publication part number 68007024010) to ensure compliance with RF energy
exposure limits.
For a list of Motorola-approved antennas, and other accessories, visit the following web site
which lists approved accessories: http://www.motorola.com/radiosolutions
DOCUMENT HISTORY
The following major changes have been implemented in this manual since the previous edition:
Edition Description Date
6878422A01-A Initial edition Mar, 2009
iii
6878422A01-B Added VHF and UHF1 band information (Chapter 8,
9, 10, 11, 12, 13)
August, 2009
iv
Notes
Table of Contents v
Table of Contents
Copyright ........................................................................................................ i
Safety Information......................................................................................... ii
Document History ........................................................................................ iii
Chapter 1 Maintenance ........................................................................ 1-1
1.1 Preventive Maintenance ................................................................................................................ 1-1
1.2 Inspection ...................................................................................................................................... 1-1
1.3 Cleaning......................................................................................................................................... 1-1
1.4 Safe Handling of CMOS and LDMOS............................................................................................ 1-2
1.5 General Repair Procedures and Techniques ................................................................................ 1-2
Chapter 2 Test Equipment, Service Aids, and Service Tools........... 2-1
2.1 Test Equipment.............................................................................................................................. 2-1
2.2 Service Aids................................................................................................................................... 2-2
Chapter 3 DC Power Distribution........................................................ 3-1
3.1 DC Regulation and Distribution ..................................................................................................... 3-1
Chapter 4 Controller Theory of Operation.......................................... 4-1
4.1 RX Audio Circuit ............................................................................................................................ 4-1
4.1.1 Audio processor IC (U102) ............................................................................................... 4-1
4.1.1.1 RX Audio Processing......................................................................................... 4-1
4.1.1.2 RX Tone PL/Digital PL Decode Filtering............................................................ 4-2
4.1.2 Audio Amp ........................................................................................................................ 4-2
4.1.3 Internal and External Speaker .......................................................................................... 4-2
4.2 TX Audio Circuit............................................................................................................................. 4-3
4.2.1 MIC and External MIC ...................................................................................................... 4-3
4.2.2 4-order 4 kHz Low-Pass Filter (U501-C, D) ...................................................................... 4-3
4.2.3 Audio processor IC (U102) ............................................................................................... 4-3
4.2.3.1 TX Audio Processing ......................................................................................... 4-3
4.2.3.2 Tx Tone PL/Digital PL Encode Filtering............................................................. 4-4
4.2.4 TX audio amplifier and 6 order 3 kHz Low-Pass filter....................................................... 4-4
4.2.5 TX modulation Adjustment................................................................................................ 4-4
4.3 Microprocessor Circuitry ................................................................................................................ 4-4
4.3.1 Memory Usage ................................................................................................................. 4-5
4.3.2 Control and Indicator Interface ......................................................................................... 4-5
4.3.3 Interface to USB programming ......................................................................................... 4-5
4.3.4 Storage of Customer-Specific Information........................................................................ 4-5
4.3.5 Sensing of VOX operating ................................................................................................ 4-5
4.3.6 Microprocessor Power-on reset Routine .......................................................................... 4-5
4.3.7 Microprocessor 7.3728 MHz Clock................................................................................... 4-5
vi Table of Contents
4.3.8 Battery indicator ................................................................................................................ 4-5
Chapter 5 435 – 480 MHz UHF2 Theory Of Operation ....................... 5-1
5.1 Introduction .................................................................................................................................... 5-1
5.2 UHF2 Receiver .............................................................................................................................. 5-1
5.2.1 Receiver Front End ...........................................................................................................5-2
5.2.2 Receiver Back End ........................................................................................................... 5-2
5.3 UHF2 Transmitter .......................................................................................................................... 5-3
5.3.1 Power Amplifier................................................................................................................. 5-3
5.3.2 Antenna Switch ................................................................................................................. 5-3
5.3.3 Harmonic Filter..................................................................................................................5-3
5.3.4 Auto Power Control........................................................................................................... 5-4
5.4 UHF2 Frequency Generation Circuitry........................................................................................... 5-4
5.4.1 Reference Oscillator (12.8 MHz VCTCXO)....................................................................... 5-4
5.4.2 PLL IC Prescaler and Comparator.................................................................................... 5-5
5.4.3 Voltage Doubler and Charge Pump .................................................................................. 5-5
5.4.4 Loop Filter ......................................................................................................................... 5-5
5.4.5 Dual VCO.......................................................................................................................... 5-5
5.5 Keypad........................................................................................................................................... 5-6
Chapter 6 UHF2 Troubleshooting Tables........................................... 6-1
6.1 Troubleshooting Table for Receiver (UHF2) .................................................................................6-1
6.2 Troubleshooting Table for Synthesizer (UHF2) ............................................................................ 6-2
6.3 Troubleshooting Table for Transmitter (UHF2) .............................................................................6-3
6.4 Troubleshooting Table for Board and IC Signals (UHF2) ............................................................. 6-4
Chapter 7 UHF2 Schematic Diagrams, Overlays, and Parts Lists ... 7-1
7.1 Introduction .................................................................................................................................... 7-1
7.1.1 Notes For All Schematics and Circuit Boards ...................................................................7-1
7.1.2 Four Layer Circuit Board...................................................................................................7-3
7.2 Speaker and Microphone Schematic .............................................................................................7-3
7.2.1 Speaker and Microphone Parts List.................................................................................. 7-3
7.3 Circuit Board/Schematic Diagram and Parts List (UHF2: 435–480 MHz)...................................... 7-4
7.3.1 Parts List ......................................................................................................................... 7-16
Chapter 8 136 – 174 MHz VHF Theory Of Operation.......................... 8-1
8.1 Introduction .................................................................................................................................... 8-1
8.2 VHF Receiver................................................................................................................................. 8-1
8.2.1 Receiver Front End ...........................................................................................................8-2
8.2.2 Receiver Back End ........................................................................................................... 8-2
8.3 VHF Transmitter............................................................................................................................. 8-3
8.3.1 Power Amplifier................................................................................................................. 8-3
8.3.2 Antenna Switch ................................................................................................................. 8-3
8.3.3 Harmonic Filter..................................................................................................................8-3
8.3.4 Auto Power Control........................................................................................................... 8-4
8.4 VHF Frequency Generation Circuitry............................................................................................. 8-4
8.4.1 Reference Oscillator (12.8 MHz VCTCXO)....................................................................... 8-4
8.4.2 PLL IC Prescaler and Comparator.................................................................................... 8-5
Table of Contents vii
8.4.3 Voltage Doubler and Charge Pump.................................................................................. 8-5
8.4.4 Loop Filter......................................................................................................................... 8-5
8.4.5 Dual VCO.......................................................................................................................... 8-5
8.5 Keypad........................................................................................................................................... 8-6
Chapter 9 VHF Troubleshooting Tables ............................................. 9-1
9.1 Troubleshooting Table for Receiver (VHF) ................................................................................... 9-1
9.2 Troubleshooting Table for Synthesizer (VHF) .............................................................................. 9-2
9.3 Troubleshooting Table for Transmitter (VHF) ............................................................................... 9-3
9.4 Troubleshooting Table for Board and IC Signals (VHF) ............................................................... 9-4
Chapter 10 VHF Schematic Diagrams, Overlays, and Parts Lists.... 10-1
10.1 Introduction.................................................................................................................................. 10-1
10.1.1 Notes For All Schematics and Circuit Boards ................................................................. 10-1
10.1.2 Four Layer Circuit Board................................................................................................. 10-3
10.2 Speaker and Microphone Schematic........................................................................................... 10-3
10.2.1 Speaker and Microphone Parts List................................................................................ 10-3
10.3 Circuit Board/Schematic Diagram and Parts List (VHF: 136–174 MHz)...................................... 10-1
10.3.1 Parts List....................................................................................................................... 10-14
Chapter 11 403 – 447 MHz UHF1 Theory Of Operation ..................... 11-1
11.1 Introduction.................................................................................................................................. 11-1
11.2 UHF1 Receiver ............................................................................................................................ 11-1
11.2.1 Receiver Front End......................................................................................................... 11-2
11.2.2 Receiver Back End .........................................................................................................11-2
11.3 UHF1 Transmitter ........................................................................................................................ 11-3
11.3.1 Power Amplifier............................................................................................................... 11-3
11.3.2 Antenna Switch............................................................................................................... 11-3
11.3.3 Harmonic Filter ............................................................................................................... 11-3
11.3.4 Auto Power Control......................................................................................................... 11-4
11.4 UHF1 Frequency Generation Circuitry ........................................................................................ 11-4
11.4.1 Reference Oscillator (12.8 MHz VCTCXO) .................................................................... 11-4
11.4.2 PLL IC Prescaler and Comparator.................................................................................. 11-5
11.4.3 Voltage Doubler and Charge Pump ................................................................................ 11-5
11.4.4 Loop Filter....................................................................................................................... 11-5
11.4.5 Dual VCO........................................................................................................................ 11-5
11.5 Keypad......................................................................................................................................... 11-6
Chapter 12 UHF1 Troubleshooting Tables......................................... 12-1
12.1 Troubleshooting Table for Receiver (UHF1) ............................................................................... 12-1
12.2 Troubleshooting Table for Synthesizer (UHF1) .......................................................................... 12-2
12.3 Troubleshooting Table for Transmitter (UHF1) ........................................................................... 12-3
12.4 Troubleshooting Table for Board and IC Signals (UHF1) ........................................................... 12-4
Chapter 13 UHF1 Schematic Diagrams, Overlays, and Parts Lists . 13-1
13.1 Introduction.................................................................................................................................. 13-1
viii Table of Contents
13.1.1 Notes For All Schematics and Circuit Boards ................................................................. 13-1
13.1.2 Four Layer Circuit Board................................................................................................. 13-3
13.2 Speaker and Microphone Schematic........................................................................................... 13-3
13.2.1 Speaker and Microphone Parts List ................................................................................ 13-3
13.3 Circuit Board/Schematic Diagram and Parts List (UHF1: 403–447 MHz).................................... 13-1
13.3.1 Parts List ....................................................................................................................... 13-13
Appendix A Warranty, Service Support, and Replacement Parts .......A-1
A.1 Scope of Manual ............................................................................................................................A-1
A.2 Warranty ........................................................................................................................................A-1
A.2.1 Warranty Period and Return Instructions..........................................................................A-1
A.2.2 After Warranty Period .......................................................................................................A-1
A.2.3 Piece Parts........................................................................................................................A-2
List of Figures ix
List of Figures
Figure 2-1. Programming/Test Cable (PMDN4077_R)....................................................................... 2-3
Figure 2-2. Cloning Cable (PMDN4076_R) ........................................................................................ 2-3
Figure 2-3. Wiring of the Connectors.................................................................................................. 2-3
Figure 3-1. DC Power Distribution Block Diagram.............................................................................. 3-1
Figure 4-1. RX Audio Circuit ............................................................................................................... 4-1
Figure 4-2. TX Audio Circuit ............................................................................................................... 4-3
Figure 5-1. UHF2 Receiver Block Diagram ........................................................................................ 5-1
Figure 5-2. UHF2 Transmitter Block Diagram .................................................................................... 5-3
Figure 5-3. UHF2 Frequency Generation Unit Block Diagram ........................................................... 5-4
Figure 5-4. Keypad Block Diagram..................................................................................................... 5-6
Figure 7-1. Four–Layer Circuit Board: Copper Steps in Layer Sequence .......................................... 7-3
Figure 7-2. Speaker and Microphone Schematic ............................................................................... 7-3
Figure 7-3. UHF2 (435–480 MHz) Receiver Schematic Diagram....................................................... 7-4
Figure 7-4. VCO and PLL Schematic Diagram................................................................................... 7-5
Figure 7-5. Transmitter Schematic Diagram....................................................................................... 7-6
Figure 7-6. Microprocessor and Keypad Schematic Diagram ............................................................ 7-7
Figure 7-7. Audio Power Amplifier and External Audio Schematic Diagram ...................................... 7-8
Figure 7-8. Switches and Battery Schematic Diagram ....................................................................... 7-9
Figure 7-9. Transmitter Audio Filter and Sub-tone Schematic Diagram ........................................... 7-10
Figure 7-10. UHF2 (435–480 MHz) Mainboard Top Side: PCB No. 8431BEACON200..................... 7-11
Figure 7-11. UHF2 (435–480 MHz) Mainboard Bottom Side: PCB No. 8431BEACON200 ............... 7-12
Figure 7-12. UHF2 (435–480 MHz) Sub Circuit Board Top View: PCB No. 8421BEACON100......... 7-13
Figure 7-13. UHF2 (435–480 MHz) Sub Circuit Board Bottom View: PCB No. 8421BEACON100.... 7-14
Figure 7-14. UHF2 (435–480 MHz) Keypad Board: PCB No. 8422BEACON100 .............................. 7-15
Figure 8-1. VHF Receiver Block Diagram...........................................................................................8-1
Figure 8-2. VHF Transmitter Block Diagram....................................................................................... 8-3
Figure 8-3. VHF Frequency Generation Unit Block Diagram.............................................................. 8-4
Figure 8-4. Keypad Block Diagram..................................................................................................... 8-6
Figure 10-1. Four–Layer Circuit Board: Copper Steps in Layer Sequence ........................................ 10-3
Figure 10-2. Speaker and Microphone Schematic ............................................................................. 10-3
Figure 10-3. VHF (136–174 MHz) Receiver Schematic Diagram....................................................... 10-1
Figure 10-4. VCO and PLL Schematic Diagram................................................................................. 10-2
Figure 10-5. Transmitter Schematic Diagram..................................................................................... 10-3
Figure 10-6. Microprocessor and Keypad Schematic Diagram .......................................................... 10-4
Figure 10-7. Audio Power Amplifier and External Audio Schematic Diagram .................................... 10-5
Figure 10-8. Switches and Battery Schematic Diagram ..................................................................... 10-6
Figure 10-9. Transmitter Audio Filter and Sub-tone Schematic Diagram ........................................... 10-7
Figure 10-10. Receiver Audio Filter and Sub-tone Schematic Diagram ............................................... 10-8
Figure 10-11. VHF (136–174 MHz) Mainboard Top Side: PCB No. 8431BEACON400....................... 10-9
Figure 10-12. VHF (136–174 MHz) Mainboard Bottom Side: PCB No. 8431BEACON400................ 10-10
Figure 10-13. VHF (136–174 MHz)Sub Circuit Board Top View: PCB No. 8421BEACON100 .......... 10-11
Figure 10-14. VHF (136–174 MHz)Sub Circuit Board Bottom View: PCB No. 8421BEACON100 ..... 10-12
Figure 10-15. VHF (136–174 MHz) Keypad Board: PCB No. 8422BEACON100 .............................. 10-13
Figure 11-1. UHF1 Receiver Block Diagram ...................................................................................... 11-1
Figure 11-2. UHF1 Transmitter Block Diagram .................................................................................. 11-3
Figure 11-3. UHF1 Frequency Generation Unit Block Diagram ......................................................... 11-4
Figure 11-4. Keypad Block Diagram................................................................................................... 11-6
Figure 13-1. Four–Layer Circuit Board: Copper Steps in Layer Sequence ........................................ 13-3
Figure 13-2. Speaker and Microphone Schematic ............................................................................. 13-3
Figure 13-3. UHF1 (403–447 MHz) Receiver Schematic Diagram..................................................... 13-1
x List of Figures
Figure 13-4. VCO and PLL Schematic Diagram ................................................................................. 13-2
Figure 13-5. Transmitter Schematic Diagram ..................................................................................... 13-3
Figure 13-6. Microprocessor and Keypad Schematic Diagram .......................................................... 13-4
Figure 13-7. Audio Power Amplifier and External Audio Schematic Diagram .................................... 13-5
Figure 13-8. Switches and Battery Schematic Diagram ..................................................................... 13-6
Figure 13-9. Transmitter Audio Filter and Sub-tone Schematic Diagram ........................................... 13-7
Figure 13-10. UHF1 (403–447 MHz) Mainboard Top Side: PCB No. 8431BEAUHF300 .....................13-8
Figure 13-11. UHF1 (403–447 MHz) Mainboard Bottom Side: PCB No. 8431BEAUHF300 ................13-9
Figure 13-12. UHF1 (403–447 MHz) Sub Circuit Board Top View: PCB No. 8421BEACON100 ....... 13-10
Figure 13-13. UHF1 (403–447 MHz) Sub Circuit Board Bottom View: PCB No. 8421BEACON100.. 13-11
Figure 13-14. UHF1 (403–447 MHz) Keypad Board: PCB No. 8422BEACON100 ............................ 13-12
List of Tables xi
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. Recommended Test Equipment....................................................................................... 2-1
Table 2-2. Service Aids ..................................................................................................................... 2-2
Table 3-1. Voltage Regulators........................................................................................................... 3-2
Table 4-1. Radio Memory Requirements........................................................................................... 4-4
Table 6-1. Troubleshooting Table for Receiver (UHF2) .................................................................... 6-1
Table 6-2. Troubleshooting Table for Synthesizer (UHF2)................................................................ 6-2
Table 6-3. Troubleshooting Table for Transmitter (UHF2) ................................................................ 6-3
Table 6-4. Troubleshooting Table for Board and IC Signals (UHF2)................................................. 6-4
Table 9-1. Troubleshooting Table for Receiver (VHF)....................................................................... 9-1
Table 9-2. Troubleshooting Table for Synthesizer (VHF) .................................................................. 9-2
Table 9-3. Troubleshooting Table for Transmitter (VHF)................................................................... 9-3
Table 9-4. Troubleshooting Table for Board and IC Signals (VHF)................................................... 9-4
Table 12-1. Troubleshooting Table for Receiver (UHF1) .................................................................. 12-1
Table 12-2. Troubleshooting Table for Synthesizer (UHF1).............................................................. 12-2
Table 12-3. Troubleshooting Table for Transmitter (UHF1) .............................................................. 12-3
Table 12-4. Troubleshooting Table for Board and IC Signals (UHF1)............................................... 12-4
xii Notations Used in This Manual
Notations Used in This Manual
Throughout the text in this publication, you will notice the use of the following notations. These notations are
used to emphasize that safety hazards exist, and due care must be taken and observed.
Note
An operational procedure, practice, or condition that isessential to emphasize.
CAUTION indicates a potentially hazardous situation which, if not avoided,
might result in equipment damage.
Summary of Printed Circuit Boards and Bands Available xiii
Summary of Printed Circuit Boards and Bands Available
Table below lists all the bands available in this manual.
Frequency
Band
UHF2 435 – 480 MHz 1W or 4W
UHF2 – –
UHF2 – –
VHF 136 – 162 MHz 1W or 5W
VHF – –
VHF – –
UHF1 403 – 447 MHz 1W or 4W
UHF1 – –
UHF1 – –
Bandwidth Power Level PC Board Part Number Board
8431BEACON200
8421BEACON100
8422BEACON100
8431BEACON400
8421BEACON100
8422BEACON100
8431BEAUHF300
8421BEACON100
8422BEACON100
Chapter
Revision
27
1 7
17
4 10
110
1 10
313
1 13
113
xiv
Notes
Chapter 1 Maintenance
1.0 Introduction
This chapter of the manual describes:
• Preventive maintenance
• Safe handling of CMOS devices
• Repair procedures and techniques
NOTE
The Servicing of your Intrinsically Safe Radios.
In order to maintain compliance, radios that are FM Approved to intrinsically safe
standards MUST be repaired at FM audited service centers. See Further Assistance From
Motorola on page 1-2 for more information.
1.1 Preventive Maintenance
Periodic visual inspection and cleaning is recommended.
1.2 Inspection
Check that the external surfaces of the radio are clean, and that all external controls and switches
are functional. It is not recommended to inspect the interior electronic circuitry.
1.3 Cleaning
The following procedures describe the recommended cleaning agents and the methods to be
used when cleaning the external and internal surfaces of the radio. External surfaces include the
front cover, housing assembly, and battery case. These surfaces should be cleaned whenever a
periodic visual inspection reveals the presence of smudges, grease, and/or grime.
NOTE
The only recommended agent for cleaning the external radio surfaces is a 0.5% solution of a mild
dishwashing detergent in water. The only factory recommended liquid for cleaning the printed
circuit boards and their components is isopropyl alcohol (100% by volume).
Internal surfaces should be cleaned only when the radio is disassembled for servicing or
repair.
CAUTION: The effects of certain chemicals and their vapors can have harmful results on
certain plastics. Aerosol sprays, tuner cleaners, and other chemicals should be avoided.
1. Cleaning External Plastic Surfaces
The detergent-water solution should be applied sparingly with a stiff, non-metallic, shortbristled brush to work all loose dirt away from the radio. A soft, absorbent, lintless cloth or
tissue should be used to remove the solution and dry the radio. Make sure that no water
remains entrapped near the connectors, cracks, or crevices.
1-2 Introduction
2. Cleaning Internal Circuit Boards and Components
Isopropyl alcohol may be applied with a stiff, non-metallic, short-bristled brush to dislodge
embedded or caked materials located in hard-to-reach areas. The brush stroke should
direct the dislodged material out and away from the inside of the radio. Make sure that
controls or tunable components are not soaked with alcohol. Do not use high-pressure
air to hasten the drying process since this could cause the liquid to collect in unwanted
places. Upon completion of the cleaning process, use a soft, absorbent, lintless cloth to
dry the area. Do not brush or apply any isopropyl alcohol to the frame, front cover, or
back cover.
NOTE Always use a fresh supply of alcohol and a clean container to prevent contamination by
dissolved material (from previous usage).
1.4 Safe Handling of CMOS and LDMOS
Complementary metal-oxide semiconductor (CMOS) devices are used in this family of radios.
CMOS characteristics make them susceptible to damage by electrostatic 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 CMOS circuits and are especially important in low
humidity conditions. DO NOT attempt to disassemble the radio without first referring to the CMOS
CAUTION paragraph in the Disassembly and Reassembly section of the manual.
1.5 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 that meet or exceed compliance
to the European Union’s ROHS and WEEE directives (Waste Electrical and Electronic
Equipment (WEEE) Directive 2002/96/EC and Restriction of Hazardous Subtances
(ROHS) Directive 2002/95/EC). To maintain product compliance and reliability, use only
the Motorola specified parts in this manual.
For the identification of lead (Pb) free assemblies, all EPP products will carry the EPP
Marking, shown below, on the printed circuit board (PCB). This marking provides
information to those performing assembly, servicing and recycling operation on this
product, adhering to the JEDEC standard #97. The EPP Marking takes the form of a
label or marking on the PCB.
Introduction 1-3
Any rework or repair on Environmentally Preferred Products must be done using the appropriate
lead-free solder wire and solder paste as stated in the following tables:
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
Diamet
er
Weight
Table 1-2. Lead Free Solder Paste Part Number List
Motorola
Part Number
1085674C03 NC-SMQ230 900-1000KCPs
Manufacturer
Part Number
Viscosity Type Composition & Percent Metal
Brookfield (5rpm)
Type 3
(-325/+500)
(95.5%Sn-3.8%Ag-0.7%Cu)
89.3%
Liquid
Temperatur
e
217°C
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 Communications parts center listed in the “Piece
Parts” section of this manual.
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.
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.
1-4 Introduction
• 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.
Shields
Removing and replacing shields is recommended to be done with the Air Blower,
BOSCH GHG 603 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.
Chapter 2 Test Equipment, Service Aids, and Service
Tools
2.1 Test Equipment
Table 2-1 lists test equipment required to service the radios.
Table 2-1. Recommended Test Equipment
Motorola Part No. Description Characteristics Application
R2600 series or
HP 8920A
*R1074A Fluke 87 digital
*R1377A AC voltmeter 1 mV to 300 mV, 10 mega-
R1611A Dual channel
S1339A RF millivolt meter 100 μV to 3V RF, 10 kHz to
*R1013B or
*R1370A
System analyzer This item will substitute for
items with an asterisk (*)
True RMS metering,
multi-meter
Fluke 85 RF probe 500 MHz, 30 VAC max Use with Fluke 87 digital
100 MHz
oscilloscope
(Agillent)
SINAD meter or
SINAD meter with
RMS
200 kHz frequency
counter, 32-segment bar
graph with backlit display
Ohm input impedance
Two-channel, 100 MHz
bandwidth, 200 M sample
rate/sec, 2 MB memory/
channel
1 GHz frequency range
Without RMS audio
voltmeter or
With RMS audio voltmeter
Frequency/Deviation meter and
signal generator for wide-range
troubleshooting and alignment
Digital voltmeter is recommended
for AC/DC voltage and current
measurements
multi-meter for RF voltage
measurements.
Audio voltage measurements
Waveform measurements
RF level measurements
Receiver sensitivity
measurements
2-2 Test Equipment, Service Aids, and Service Tools: Service Aids
2.2 Service Aids
Table 2-2 lists the service aids recommended for working on the EP350 Series Radios. While all of
these items are available from Motorola, most are standard shop equipment items, and any
equivalent item capable of the same performance may be substituted for the item listed.
Table 2-2. Service Aids
Motorola Part
No.
PMDN4026_R Flat Ceramic Tuning Tools
(1.8mm)
PMDN4038_R Knob Remover/Chassis Opener Used to remove the front cover assembly.
PMDN4039_R Crab Eye Nut Opener Used to remove the crab eye nut.
1
PMDN4040_R
PMDN4041_R RF Adapter Adapts radio’s antenna port to BNC cabling of test
PMDN4044_R T-Head Ceramic Tuning Tool Used for tuning the VCO.
PMDN4053_R Flat Ceramic Tuning Tools
PMDN4076_R Radio to Radio Cloning Cable Allows a radio to be duplicated from a master radio by
PMDN4077_R Programming Cable Used to program the radio through Customer
PMDN4079_R GND Plate Interconnects radio’s chassis to RF Adaptor.
Radio Test Box Enables communication between the radio, test
(0.9mm)
Description Application
Used for tuning the VCO.
equipment and the computer's USB port.
equipment.
Used for tuning the VCO.
transferring programmed data from the master radio to
the other.
Programming Software and Radio Tuner.
PMDN4080_R Battery Eliminator Interconnects radio to power supply.
PMVN4161_ Customer Programming
Software on CD Rom
PMVN4165_ Tuner on CD Rom Only Motorola Service Centers or Authorized Motorola
Note: 1.Use PMDN4040BR or higher for tuning the EP350 Series radios as PMDN4040AR cannot be used to
perform this function.
Program customer option and channel data.
Service Dealers can perform this function.
Test Equipment, Service Aids, and Service Tools: Service Aids 2-3
t
Programming/Test Cable
2.5mm stereo
USB connection
Figure 2-1. Programming/Test Cable (PMDN4077_R)
2.5mm stereo
2.5mm stereo >
12
RX / TX data GND
~
Figure 2-2. Cloning Cable (PMDN4076_R)
D-D+
VBUS
1
2
GND
TX_D
RX_D
IC : CP2102
2.5mm stereo
1
VBUS
2
D-
3
D+
GND
4, 5, 6
To Computor
USB_CONNECTOR
Figure 2-3. Wiring of the Connectors
2-4 Test Equipment, Service Aids, and Service Tools: Service Aids
Notes
Chapter 3 DC Power Distribution
3.1 DC Regulation and Distribution
A block diagram of the DC power distribution throughout the radio is shown in Figure 3-1.
VCTCXO
Voltage
Doubler
10V
Charge
5V
Pump
3.3V
Audio filter
½ Vcc
VCO
RX B+
TXVB
MCU, EEPROM
PLL IC
Digital potent iometer
DTMF IC
LCD Driver
7.5V
Battery
Mech SW1
PA
APC
Driv er,
Pre-driver
SWB+
Vdd
Regulat or
Vdd
Regulat or
Key PC B
Low Batt.
detect or
Audio
Amplifier
Figure 3-1. DC Power Distribution Block Diagram
Battery voltage enters at connector J602 and is routed through SW/VOL1 to become SWB+.
This voltage is routed to:
•SW/VOL1
• TX power amplifier Q403 (via R417)
• APC circuit U401
• RX audio power amplifier U601
• 5V regulator (U505)
• 3.3V regulator (U506)
• Voltage divider R153/R154, a microprocessor A/D input which measures battery voltage
•Key PCB
3-2 DC Power Distribution: DC Regulation and Distribution
The following regulators are used:
Table 3-1. Voltage Regulators
Reference No. Description Type
U505 5V regulator TK11250
U506 3.3V regulator TK11233
U507 Voltage Doubler (10V) TC12140
The 5 V source from U505 is applied to:
• RX back end circuitry
• RX/TX audio filters
• 1/2 VCC generator
• VCO power source (Q705, Q706)
• RX B+ (Q304)
• TXVB (Q407)
• VCTCXO
The 5 V source is also applied to transistor switches Q304 and Q407. Q304 is turned on by Q305
when RX_EN (from U101 Pin 71) is high, and supplies the source to mixer, IF IC and LNA. Q407 is
turned on by Q408 when TX_EN2 (from U101 Pin 85) is high, and supplies the "TXVB" source to the
first transmitter stage Q401 base, Q402 gate, APC power source (U401 Pin 8) and ANT switch
(CR401).
The 3.3 V regulated source from U506 is applied to:
• MCU IC U101
• EEProm IC U104
• DTMF IC U103
• Audio processor IC U102
• Microphone bias circuitry
• And applied to Key PCB (LCD driver power source)
The 10 V source from U507 is applied to Charge Pump.
Chapter 4 Controller Theory of Operation
4.1 RX Audio Circuit
The RX audio circuit consists of Audio Processor IC, Audio Amplifier, Internal (INT)/External (EXT)
speaker and Sub-Audio Tones System.
Audio Processor IC (AK2347)
Audio IN
(from IF IC)
pin24
RXA1
VR3
-4 to +3.5dB/
0.5dB
Sub audio
Programmable
RX LPF TX/RX HPF
LPF
Sub audio
-6 to +6dB/
HPF
Comparator
U105-C
0.5dB
VR5
pin18
U105-A,B
(tone detect)
Figure 4-1. RX Audio Circuit
4.1.1 Audio processor IC (U102)
The RX audio from Pin 9 of U201 enters to Pin 24 of Audio processor IC.
To CPU
Scrambler/
Descrambler
U102
INT SPK.
EXT SPK.
J601
De-
emphasis
Expander VR4 SMF
-18, -4.5 to +4.5dB/
0.25dB
Audio Amp.
OUT-
OUT+
U601
IN-
IN+
SVR
Audio Mute
pin21
Vol1
control
• RX A: An operational amplifier used for gain adjustment of the receive demodulation signal
from Pin 9 of U201. The gain is unity and it acts as a buffer amplifier.
4.1.1.1 RX Audio Processing
•VR3: This circuit controls the volume for adjusting the input level of receive demodulation
signal. Adjustment range: -4.0dB to +3.5dB in 0.5dB steps.
• RX LPF: Low-pass filter to eliminate high-frequency components higher than 3 kHz which are
included in the receive demodulation signal.
• TX/RX HPF: High-pass filter to eliminate low-frequency components lower than 250 Hz which
are included in receive audio signal. This circuit is turned on and off by control register of Audio
processor IC.
• Descrambler: This circuit inverts the spectrum distribution of receive audio signals with respect
to the carrier frequency. The carrier frequency is 3.388 kHz or 3.290 kHz.
4-2 Controller Theory of Operation: RX Audio Circuit
• De-emphasis: This circuit restores the original state of signal of which high-frequency
component has been emphasized by the pre-emphasis.
• Expander: This circuit expands the signal compressed twice by the Compressor in dB scale to
restore the original signal state.
•VR4: This circuit controls the volume for adjusting the RX output level.
Adjustment range: -18.0dB, -4.5dB to +4.5dB in 0.25dB steps.
•SMF: Smoothing filter to eliminate the high-frequency and clock components generated in the
Audio processor IC.
4.1.1.2 RX Tone PL/Digital PL Decode Filtering
• Sub-audio Programmable LPF: Low-pass filter to eliminate components of the RXA1 signal.
This circuit is controlled by the internal registers and by the audio processor IC for cut-off
frequency.
•VR5: This circuit controls the volume for adjusting the output level from the sub-audio LPF
signal. Adjustment range: -6.0dB, +6.0dB in 0.5dB steps
The sub-audio tone of U102 Pin 18 output pass through switchable high-pass filter U105. This filter
(U105-A, B) has 4 different high pass cut-off frequencies which can be selected accordingly to the
sub-tone audio. This filter (U105-A, B) filters the unwanted sub-tone. The tone of U105-B output
passed through U105-C comparator, which acts as a squaring circuit. This output signal is then sent
to microprocessor Pin 3. The micro-processor then decodes CTCSS and CDCSS from this square
signal.
4.1.2 Audio Amp
The de-emphasized audio signal from Pin 21 of audio processor IC passes through volume control
(SW/VOL1) and is amplified by U601BTL audio amplifier to a sufficient level to drive a loud speaker.
U601 has mute/un-mute function controlled by audio-mute control (Pin 83) of CPU. When U601
Pin 1 is low, the audio amp goes to active (un-mute) mode. When U601 Pin 1 is high, the audio amp
goes to mute mode.
4.1.3 Internal and External Speaker
When no external speaker is plugged into J601, the RX audio is passed through to the internal
speaker. When an external speaker is plugged into J601, the internal speaker is cut-off from the
rest of the circuit and RX audio is passed through the external speaker.
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