Sendo M550 Service Manual

M550/M551 Level 3 Service Manual Page1

MM555500//MM555511 SSEERRVVIICCEE MMAANNUUAALL LLEEVVEELL 33

M550/M551 Level 3 Service Manual Page2

Contents:

Section 1. Introduction

Section 2. Repair Precautions

Sendo guidelines for safe and productive repair work.

Section 3. Product Features and Specifications

General features, technical specifications and warranty details for the M550.

Section 4. Product Architecture

Functional block diagrams of the RF and logic circuit architecture. Board layouts are also provided which highlight the main functional areas such as audio, power supplies and RF circuitry.

Section 5. Product Servicing and Rework Guide

Level 3 repair items, recommended rework equipment and guidelines. Also included are the assembly-disassembly instructions.

Section 6. Trouble Shooting

Detailed circuit description and repair information to help debug problems and faults.

Section 7. Software Download

The service centre software download set-up process and its operation.

Section 8. Parts Info

The M550 Parts list including exploded view.

M550/M551 Level 3 Service Manual Page3

Section 1. Introduction

Welcome to the level 3 Service Manual for the Sendo M550/M551. This manual will guide you to repairing the modules used in the Sendo M550/M551 models. The M551 is the United States variant – for GSM 850/1900 Mhz.

This manual will help guide you through all repair aspects of the M550/M551 and provide detailed information on the product.

X102 32 Khz Xtal

M550/M551 Level 3 Service Manual Page4

Section 2

Repair Precautions

M550/M551 Level 3 Service Manual Page5

Important!

Please read the following cautions, notes and warnings

before progressing through this manual or undertaking

any repair action. Remember: SAFETY

FIRST!

AC Main Lead/Power Cord:

Always ensure that ALL AC mains leads used in the repair area are in good condition and checked regularly. Care must be taken not to damage the lead as this could result in fire or electric shock.

Battery Pack:

ONLY use original Sendo supplied batteries and chargers with the M550/M551. DO NOT short the battery terminals together.

Keep the battery pack away from fire and sources of ignition.

Remember to recharge the battery pack after each use.

Before YOU Power up the M550/M551:

• Only switch on the telephone’s power once the test or installation set-up is complete.

• Switching on at the wrong time may result in electric shock or damage to system

components.

• Always ensure that the power is switched off before making connections / disconnection’s.

• It is important to check that the correct DC voltage is applied to the M550/M551 to prevent electrical damage.

M550/M551 Level 3 Service Manual Page6

Component Polarity +/-

Always check the polarity of connections and components before soldering. Particular attention must be paid to I.C’s, diodes, transistors, capacitors and any other semiconductor device that is polarity dependent.

Electrostatic Damage (ESD):

Semiconductor devices are easily damaged by electrostatic discharge. Many of the procedures detailed in this manual involve disassembly of the equipment and therefore handling of the printed circuit boards. To protect these devices from ESD a wrist strap connected to ground must be worn. In addition to this the work surface must be covered with an anti-electrostatic mat, which should also be grounded.

If printed circuit boards are to be stored without being re-assembled into their equipment, then they must be kept in an anti-electrostatic bag.

Grounding:

Each piece of test equipment should be electrically grounded. A third (grounding) pin is provided as a safety feature. Ensure that the electrical outlet also contains this feature.

Cosmetic Protection during Repair Work:

Always ensure that the working surface is kept clean and free from abrasive materials.

The LCD is very susceptible to scratches and damage. It should be covered with clear adhesive vinyl while the equipment is disassembled.

Storage of Faulty Components:

Any components that are replaced due to failure should be kept safely in an anti-electrostatic container. Sendo’s Quality or Research & Development Departments may require them to make quality and reliability investigations.

M550/M551 Level 3 Service Manual Page7

No Fault Found Equipment:

In some cases the reported symptom may not be apparent. You may subject the equipment to a controlled amount of stress, vibration and temperature variation to see if the fault occurs. Care should be taken not to apply excessive stress or vibration or extreme temperature variations as further faults may develop.

Soldering and Disordering :

Fast, accurate and high quality soldering is required to minimise the risk of heat damage to the electronic components. ALL rework must follow methods set out in IPC- 7711 (Rewpork of Electrical Assemblies). NO joint should be touched up more than twice. Wire modifications are not permitted. BGA or fine pitch devices may not be reflowed more than once.

Short Circuits:

Care must be taken to avoid short circuits. Soldering, solder dust, screws, metal clippings, metal wrist watches etc. can cause short circuits on PCBs which may result in component damage.

Test Equipment Calibration:

Your test equipment should be calibrated before use. Frequent calibration is essential to ensure high quality and reliable repairs.

Cleaning:

Before cleaning ensure that the telephone is switched off and disconnected from the power source. Cleaning should be done using a soft dry cloth. If the equipment is heavily soiled a soft cloth soaked in a mild synthetic detergent diluted in water may be used.

Never use benzene or any other chemicals to clean the equipment.

RF Shielding:

M550/M551 Level 3 Service Manual Page8

It is advisable to carry out detailed measurements and repair (in particular RX) in a shielded area to minimise RF interference.

AC Adapter and Battery Charger:

The AC adapter and battery chargers are for indoor use only. Ensure that the devices are not exposed to rain or moisture.

Electrical Safety:

Electrical equipment is hazardous if misused. Any repairs must be carried out with care and only by authorised personnel. Ensure all power sources are switched off and power cords removed before undertaking any repairs.

Hazardous Waste:

The battery pack, if incorrectly disposed of, is an environmental hazard. It must be disposed of in accordance with the regulations of the country concerned. Never dispose of the battery pack in fire or water.

Confidentiality:

The circuitry within this equipment contains several components that are regarded as company confidential. Only use Sendo authorised parts as replacements.

RF Injury:

To avoid RF injury, direct exposure to radio frequency energy should be avoided. In particular, exposed parts of your body (especially the eyes and face) should not come into contact with the antenna while the equipment is transmitting.

M550/M551 Level 3 Service Manual Page9

Storage Conditions:

It is recommended that the following storage conditions should be avoided to prevent damage to the equipment: Dusty. Humid.

Near to magnetic equipment.

In direct sunlight.

Ventilation:

Repair areas should be well ventilated and fume extraction systems should be installed where necessary. Potential hazardous substances are solder fumes, flux, alcohol etc.

PCB Handling:

It is recommend that cotton or latex gloves are worn during repair work. This is to protect your hands from chemical contamination and to protect the PCBs from fingerprints and humidity.

SIM Card:

• Do not bend.

• Clean by using a soft dry cloth.

• Please note that a modified SIM card will be required to perform conducted rf

measurements via the rf switch. See section 5. Product Servicing and Rework Guide.

M550/M551 Level 3 Service Manual Page10

Section 3

Product Features and

Specifications

M550/M551 Level 3 Service Manual Page11

PPrroodduucctt DDeessccrriippttiioonnss

 M550 IMEI TAC code: 35188400 (M551:001031A)

 Model Type: SND550/SND551

NNeettwwoorrkk SSeerrvviicceess

 Dual Band E-GSM 900 / GSM 1800 - M550  Dual Band GSM 850 / GSM 1900 - M551  Automatic switching between bands  Manual and automatic network selection  HR / FR / EFR codec for GSM 900 / 1800  M551 includes AMR FR and AMR HR

DDiimmeennssiioonnss aanndd WWeeiigghht

Length (a)

Width (b) 19.6mm at widest point

Depth (c) 45mm at thickest point

82mm at longest point

t

a

Weight 77g

Volume 68cc

PPoowweerr MMaannaaggeemmeennt

 Talk Time: Up to 180-400 mins*  Standby Time: Up to 120-300 hours*  Game-Play up to 3 hours*

 Sim Type:  Charging time: <2 hours  Battery: Li-Ion cell - 650Ah, 3.7vdc  Linear charger (240v Euro plug, 240v UK plug, 220v China plug, 110v US

plug or 220v Australian plug)

* Battery life is Network dependent; variations may occur.

The M550/M551 works closely with the network and the standby and talk times achieved depend upon this. In particular the location of the HHP within the network, the type of SIM, reception of area messages, the use of

Micro 3V or 5V SIM

t

c

b

M550/M551 Level 3 Service Manual Page12

Full Rate speech or Enhanced Full rate speech and other factors will affect both standby and talk times.

MM555500 CCoorree FFeeaattuurrees

s

Product Features

 Clamshell design with internal antenna  Size: 77g, weight: 68cc  Dual display, outer: reverse video, 96x64 pixels  Inner colour display – up to 4096 colours  Customizable colour themes  On phone dynamic memory-up to 500 phone book entries  Colour EMS  Wap 1.2.1 colour browser and GPRS class 8  Colour games  Tegic T9 text input, built in SMS chat and SMS templates  Animated graphics and sound  Dual Band (M550:E-GSM 900/1800, M551:GSM850/1900  Stand by time up to 180-400 hours*  Talk time up to 120-300 mins*  Gameplay up to 3 hours*

*talktime and standby times depend upon network conditions and the way you use the phone.

M550/M551 Level 3 Service Manual Page13

WWaarrrraannttyy DDeettaaiills

s

Limited Warranty

Sendo International Limited (“Sendo”) warrants, subject to the exclusions and limitations set forth below, that your cellular phone, battery and accessories (collectively “Product”) is free from defects in materials and workmanship according to the following terms and conditions:

1. The limited warranty for the Product commences on the date of purchase and continues for a period of one

(1) year from that date. Upon request from Sendo, you, (the “Consumer”) must prove the date of the original purchase of the Products by dated itemised receipt.

2. The limited warranty extends to the original purchaser of the Product, the Consumer, and is not assignable

or transferable to any subsequent purchaser or user.

3. The warranty extends only to Consumers who purchase the Product in the market for its intended sale.

4. During the limited warranty period, Sendo will repair, or replace, at Sendo's sole option, any defective parts, or any

parts that will not properly operate for their intended use with new or refurbished replacement items if such repair or replacement is needed because of a malfunction or failure of the Product during normal usage. No charge will be made to the Consumer for any such parts. Sendo will also pay for the labour charges incurred by Sendo in repairing or replacing the defective parts. This warranty does not apply to any damage or failure to operate caused by use of the Product other than in accordance with the instructions contained in the User Manual, or for periodic maintenance or repair due to normal wear and tear. Sendo's limit of liability under the limited warranty shall be the actual cash value of the Product at the time the Consumer returns the Product for repair, determined by the price paid by the Consumer for the Product less a reasonable amount for usage. Sendo shall not be liable for any other losses or damages. These remedies are the Consumer's exclusive remedies for breach of warranty

5. The warranty will be invalidated if any of the following circumstances are applicable:

a) The Product has been subject to abnormal use, abnormal conditions, improper storage, exposure to

moisture or dampness, unauthorized modifications, unauthorized connections, unauthorized repair, misuse, neglect, abuse, accident, alteration, improper installation, or other acts which are not the fault of Sendo, including damage caused by shipping.

b) Physical damage to the surface of the Product, including scratches or cracks in or to the outside casing or

Liquid Crystal Display, or damages caused by dropping the Product.

c) The Product has been damaged from external causes such as liquid, water, collision with an object, or from

fire, flooding, sand, dirt, windstorm, lightening, earthquake or damage from exposure to weather conditions, an Act of God, or battery leakage, theft, blown fuse, or improper use of any electrical source, damage caused by computer or internet viruses, bugs, worms, Trojan Horses, cancelbots or damage caused by the connection to other products not recommended for interconnection by Sendo.

d) The Product has been altered or repaired by anyone other than an authorised Sendo service centre or if it

has been used with unapproved accessories or other ancillary items.

e) For adaptations or adjustments made to the Product to comply with local standards in any country other than

one for which the Product was designed and manufactured.

f) Loss of integrity of any user data stored in the Product or any storage device used in conjunction with the

Product at any time

g) The Sendo authorised service centre was not advised by the Consumer in writing of the alleged defect or

malfunction of the Product within fourteen (14) days after the expiration of the applicable limited warranty period.

M550/M551 Level 3 Service Manual Page14

h) The Product serial number plate or the accessory data code has been removed, defaced or altered.

i) The defect or failure to operate was caused by the defective function of the cellular system or by inadequate

signal reception.

6. Any implied warranty of satisfactory quality, merchantability, or fitness for a particular purpose or use, shall be

limited to the duration of the foregoing written warranty. Otherwise, the foregoing warranty is the Consumer’s sole and exclusive remedy and is in lieu of all other warranties, express or implied. Sendo does not warrant uninterrupted or error free internet or data connections. Sendo shall not be liable for special, incidental or consequential damages, including but not limited to, loss of anticipated benefits or profits, loss of savings or revenue, punitive damages, loss of use of the product or any associated equipment, loss of data, cost of capital, cost of any substitute equipment or facilities, downtime, the claims of any third parties, including customers, and injury to property, resulting from the purchase or use of the product or arising from breach of the warranty, breach of contract, negligence, strict tort, or any other legal or equitable theory, even if Sendo knew of the likelihood of such damages. Sendo shall not be liable for delay in rendering service under the limited warranty, or loss of use during the period that the product is being repaired or loss of data.

7. Some jurisdictions do not allow limitation of how long an express or implied warranty lasts and so the one year

warranty period referred to above may not apply, to you, the Consumer. Some jurisdictions do not allow the exclusion or limitation of incidental and consequential damages and so to the extent that such limitations are not allowed, the above limitations or exclusions may not apply, to you, the Consumer. This limited warranty gives the Consumer specific legal rights and the Consumer may also have other legal rights under the legislation of some jurisdictions. These legal rights vary from jurisdiction to jurisdiction and are not prejudiced by anything contained in this limited warranty. It also means that in some jurisdictions our responsibility to you the Consumer may be more extensive than in other jurisdictions.

8. The Consumer shall take the following steps to make a claim under this limited warranty:

a) Please do not ship the Product for service without first contacting the nearest Sendo Authorised Service

Centre.

b) Contact information for the world-wide network of Sendo authorised service centres is available at

www.sendo.com

c) If the Product qualifies for in-warranty service, the Consumer must prove the date of the original purchase of

the Products by a dated proof of purchase.

d) Back up all data. If the Consumer has sensitive information stored on the Product copy it to another device

and delete it from the Product before repair.

e) The Consumer must ship the Product prepaid and insured. Expenses related to removing the Product from

an installation are not covered under this limited warranty.

f) If the Product is returned for service and the Product is deemed out of warranty under the terms and

conditions of this warranty, the Consumer will be notified and given an estimate of the applicable charges. If the estimate is refused a minimum service fee for collection, inspection and quotation of said product would be due.

9. Subject to any more extensive legal rights granted to the Consumer by law of the Consumer’s jurisdiction, Sendo

neither assumes nor authorizes any authorised service centre or any other person or entity to assume for it any other obligation or liability beyond that which is expressly provided for in this limited warranty including the provider or seller of any extended warranty or service agreement.

10. This is the entire warranty between Sendo and the Consumer, and supersedes all prior and contemporaneous

agreements or understandings, oral or written, and all communications relating to the Product, and no representation, promise or condition not contained herein shall modify these terms.

11. This limited warranty allocates the risk of failure of the Product between the Consumer and Sendo. The allocation

is recognized by the Consumer and is reflected in the purchase price of the Product.

12. Diagnostic instructions and other service information is available free of charge at www.sendo.com

out of warranty repair costs and charges is available at www.sendo.com

. Information on

.

M550/M551 Level 3 Service Manual Page15

Warranty Details

Identifying the manufacturing date on a unit.

EXAMPLE,

First LETTER = YEAR Second LETTER = MONTH

DD = 2003, April

NOTE:

THE CODES HAVE ONLY BEEN ISSUED ON MANUFACTURED UNITS AFTER SEPTEMBER 2001.

M550/M551 Level 3 Service Manual Page16

The Table below shows the manufacturing dates and their codes.

WWaarrrraannttyy TTaabbllee

CODE MANUFACTURED DATE OUT OF WARRENTY END OF

BI

BJ

BK

BL CA CB CC CD CE

CF CG CH

CI

CJ CK

CL DA DB DC DD DE

DF DG DH

DI

DJ DK

DL EA EB EC ED

EE

EF

SEPT 2001 NOV 2002

OCT 2001 DEC 2002 NOV 2001 JAN 2003 DEC 2001 FEB 2003

JAN 2002 MAR 2003 FEB 2002 APR 2003

MAR 2002 MAY 2003

APR 2002 JUNE 2003

MAY 2002 JULY 2003

JUNE 2002 AUG 2003

JULY 2002 SEPT 2003

AUG 2002 OCT 2003

SEPT 2002 NOV 2003

OCT 2002 DEC 2003 NOV 2002 JAN 2004 DEC 2002 FEB 2004

JAN 2003 MAR 2004 FEB 2003 APR 2004

MAR 2003 MAY 2004

APR 2003 JUNE 2004

MAY 2003 JULY 2004

JUNE 2003 AUG 2004

JULY 2003 SEPT 2004

AUG 2003 OCT 2004

SEPT 2003 NOV 2004

OCT 2003 DEC 2004 NOV 2003 JAN 2005 DEC 2003 FEB 2005

JAN 2004 MAR 2005 FEB 2004 APR 2005

MAR 2004 MAY 2005

APR 2004 JUNE 2005

MAY 2004 JULY 2005

JUNE 2004 AUG 2005

M550/M551 Level 3 Service Manual Page17

Section 4

Product Architecture

M550/M551 Level 3 Service Manual Page18

r

Section.1: M550 Product Structure – Exploded view

Outer Lens Assy

Screw (4pc)

Outer Ring Assy

LCD Module

FPC

Front Hsg Assy

Keypad

Metal-dome

Mic Gasket

Inner Hsg Assy

Lens Assy

Hinge

Battery

Holde

SIM

PCBA

Screw (2pc)

Battery

Battery Cover

M550/M551 Level 3 Service Manual Page19

Logic circuit Architecture

Part a: Audio Circuits and SIM Interface

IOTA

IC200

VOICE BAND SERIAL PORT

K3

G5

H5

F5

VOIC BAND CODER/ DECODER

J9

J10

E

SIM_IO

SIM_CLK

SIM_RST

K9

C7

G7

J8

J7 H7

BB_VCLK

BB_VFS

BB_VDX

BB_VDR

(Buzzer)

BB_EARP

BB_EARN

(Ear Piece)

SIM_VCC

IO VDD

CLK

RST

BB_MIC_REF_P

BB_MICP

BB_MICN

BUZZ_EN T401

BB_SIM_IO

BB_SIM_CLK

BB_SIM_RST

SIM Reader (X402)

BB_AUX_MIC

MIC

N12

M13

N13

P14

CALYPSO

K7

IC100

X200

(Audio Jack)

AUXOP

3

2

Part b:

M550/M551 Level 3 Service Manual Page20

Part b: Logic Circuit Block Diagram

CHGR

IC200

IC100

(X102 – 32Khz)

The main functional blocks of Calypso (IC100) are:

• ARM Megamodule (ARM7TDMIE)

• DSP Megamodule (S28C128)

• Memory Interface & Memory Protection Unit

• Interrupt Handler (INTH)

• Clock Management (CLKM)

• Timers

• General Purpose IO (ARMIO)

• UART – IRDA and UART – MODEM

• UWire Interface (UWIRE)

• I2C Master Serial Interface (I2C)

• Serial Port Interface (SPI)

• Pulse Width Tones (PWT)

• Pulse Width Light (PWL)

• Light Pulse Generator (LPG)

• Debug Unit (DU)

The main functional blocks of IOTA (IC200) are:

• Automatic Frequency Control Unit

• Auxiliary Drivers

• Automatic Power Control Unit

• Baseband Codec

• Back up Battery Switch, Battery Charger Control

• Baseband Up / Down Link, Baseband Serial Port

• Clock Generator

• LDO Voltage Regulators, Voltage Reference, Power Control

• Monitoring Analogue to Digital Converter

• SIM interface

• Time Serial Port, Test Access Port

• Microcontroller Serial Port

• Voice band Codec

• Voice Serial Port

Flash

SRAM

IC300

M550/M551 Level 3 Service Manual Page21

A

Section.2: Radio Architecture

Part a: Receiver Block Diagram

IC500 RF Switch

SW

saw

6 7 9 10

PCS GSM

20 19 22 21

saw

LPF

ADC

1 2 ION IOP 12 11

Channel filter

DAC

IC600

Demodulator

HPF

LPF

Π/2

IC601

IF Mixer

IOP ION CLKP CLKN

100 KHz

NT

13 RF_LON 23

12 RF_LOP 24

7

RF_CLK_13M

4 5 2 3

D9 D10 C9 C10

003

IC100

CALYPSO

PDNB RF_TPU_DATA_OUT (SDO)

3

RF_TPU_DATA IN (SDI)

IC602

Synthesiser

RF PLL

7

3

IICC660033

((1133MMhhzz))

RF_AFC

IICC220000

IOTA

RF_IP RF_IN

RX = I+Q

RF_QP RF_QN

M550/M551 Level 3 Service Manual Page22

)

part b: Transmitter Block Diagram

RF_PA_CTL_EN 3

QP QN IP IN

VCCOUT

9 10 11

7 6 1

VRAMP

÷1 DCS ÷2 GSM

(IC200)

TX_VCO_GSM TX_V CO_PCS

IC700

25 24

IC601

LPF

∅detector

LPF

OFFSET PLL

÷

TX = I+Q

IICC220000 ((IIOOTTAA))

EGSM_PA_TX

PCS_PA_TX

Power Amps

(PA

13 RF_LON 24

14 RF_LOP 23

10 IF_ LON 27

11 IF_ LOP 28

IOP ION CLKP CLKN

M550/M551 Doc SP11498 Rev:01 Aug03

1

11

IC500 RF Switch

LPF

HPF LP F

ANT

RF_AFC (IC200)

MF501

IICC660033

13Mhz Reference

RF PLL

IC602

IF PLL

3

IICC660000

9

2

V

CXO_13MHZ

3

7

PDNB RF_TPU_DATA_OUT (SDO) RF_TPU_DATA IN (SDI)

M550/M551 Level 3 Service Manual Page23

)

Section.3: M550 Functional Areas

Part a: Keypad, MIC and Backlight Area’s

In this section are shown the locations of the main keypad, backlight and Mic locations.

Side.1

X404: MIC

Keypad Area (Shown without Metaldome sheet fitted

MF_110: Flip detect contact pad

Backlight LED’s (D402-D410)

M550/M551 Level 3 Service Manual Page24

p

Section.3: Functional Areas – Cont’d

Part b: RF and Logic functional blocks

Here are shown the main functional parts of the logic and RF circuits.

Baseband Circuitry area (in blue)

Side.2

X402 - SIM Interface

X501 – Antenna

RF Switch

RF Circuitry areas (in grey)

X403 Connector (Connects PCB to LCD Module via *FPC).

IC407 Sound Synthesiser

PA

IC504 - Antenna

IC700 – TX Power Amplifier

and associated circuit.

X400 - Battery Connector and DC

ower supply

Non-replaceable Parts IC100 “Calypso” (BGA-Underfilled) IC200 “IOTA (BGA –Underfilled) IC301 Flash/SRAM – Underfilled) IC405 LCD Driver IC700 Power Amplifier Shielding Frames (BB & RF)

X200 - Audio Jack and

charging socket.

M550/M551 Level 3 Service Manual Page25

IC603 13Mhz Clock

Main RF Circuit devices:

IC500: TX/RX path switching IC IC501: RF 2.8V POWER SUPPLY (VCC_2V8_RF) IC600: RX Demodulator IC601: IF+RF Modulator and Mixer IC602: IF+RF Synthesisor (PLL- Phase Locked Loop) X501: Mechanical rf switch IC603:13Mhz Clock IC502: GSM1800 Rx band pass filter IC503: GSM900 Rx band pass filter IC504: Antenna

X102 32 Khz Xtal

Page:26

M550/M551 Level 3 Service Manual

Section 5

Product Servicing

Page:27

M550/M551 Level 3 Service Manual

5.1 Level 1-2 Repair Items

Administration Checks

- Warranty Check

- Phone and Accessories

- DOA Filter Analysis (if required)

- Checking Fault report from customer

Level 1

- NFF

- SWAP

- Outer Bezel

- Inner Bezel

- Battery Cover

- Charger

- Battery

- Accessories

Level 2

- Labels

- Software Upgrade/Blocked Units

- Battery Holder

- Inner Housing

- Outer Ring

- Front Housing

- Keypad

- Board to Board FPC (Flexible Plastic Connector)

- Shielding can covers (Baseband+RF)

- Hinge assembly

- Metaldome

- Mic Gasket

- LCD Module (Replacement only)

- PCB cleaning

- Discreet components which just require soldering to replace

o Charger Socket o Sim Connector o Battery Connector o Mic o Buzzer, Vibrator and Earpiece (Speaker) o Backlight LED’s o Antenna

Level 3

- Components that need replacing after test equipment de-bug analysis

- Internal DAC level calibration, setting internally in phone

- Re-programming IMEI – Security

NOTE : Level 3 repair is restricted on the SND550 as some IC’s are under filled.

Page:28

M550/M551 Level 3 Service Manual

5.2 General Quality Guidelines for Rework

The following guidelines should be followed when either reworking joints or replacing electronic parts.

• All rework must follow the methods described in part 5.3b – “Prefered rework methods” and to standard IPC-7711 (Rework of Electric/Electronic Assemblies).

• No joint may be touched-up more than twice.

• Wire modifications are not permitted.

• Any BGA devices on M550, which are underfilled must not be reworked or

replaced.

5.3a Recommended Equipment for Repair

Rework Tools

Soldering Iron: - Lockable temperature-regulated soldering iron station.

E.g. JBC AM6000, Weller WSD80 or Metcal MX-500

Hand Tweezers: - ESD safe flat rounded point Solder Braid: - Multicore AA or Chemtronics 60-2-10 (size #2) Solder: - Tin/Copper Lead Free (0.5 – 1.0mm diameter) Flux: - Cobar 390RX Flux Applicator: - Boncote BON-102 Torque Driver:- Calibrated to 10Ncm (+/- 1cNm) with bit Posidrive size “0” Protective Gloves:- Disposable Latex gloves / Finger Cots. Cover opening Tool* - Available from Sendo.

Cover Opening tool

Page:29

Adaptor fitted to battery eliminator.  RF Note: Can only be used with  battery eliminator.

Gold Guard Pen:- (for cleaning all contact pads) as below:-

M550/M551 Level 3 Service Manual

This item is available from: RS Components Ltd (Part no: 298-7779), Website:rswww.com

Electronic Equipment

Digital Multimeter (DMM) 5V DC Power Supply GSM Test Set PC with Windows XP or 2000

Battery Eliminator* :- For software downloading and powering unit. Can also be used

to perform RF measurements**.

**RF adaptor (optional) must also be fitted to perform measurements).

* Please contact Sendo for Details of aquiring these items

Page:30

M550/M551 Level 3 Service Manual

Leaded RF adaptor fitted with support collar*:- for performing RF measurements of

M550/M551 if using standard battery. Plugs directly into rear of M550/M551.

Collar fitted to RF adaptor

Leaded RF adaptor “without" Collar

RS232 Interface Box with 9 VDC power supply and serial cable*

Regulated 9vdc Power Supply for RS232 interface box.

Used to provide DC power to the RS232 Interface Box.

UK Type

EU Type

Page:31

DC Jack/bannana Leads * For power connection from 5V DC power supply to battery eliminator.

GSM Test SIM :- To perform RF tests on the unit a modified test SIM must be used. A

portion of the test SIM needs to be removed as per the diagram below:-

This enables the RF adaptor(s) access to the RF switch (X501) on the rear of the unit.

* Please contact Sendo for Details of aquiring these items

This portion is removed

M550/M551 Level 3 Service Manual

M550/551 Handling Precautions

Whenever the M5** is either disassembled or assembled extreme care must be taken in handling any of its parts. Special attention must be paid when handling the colour LCD module, which can easily be scratched or damaged. Soft cotton gloves should be worn AT ALL TIMES when handling any of the M5XXs parts.

For your own safety and to protect the product from damage please observe the guidelines listed in Section 1: Repair Precautions.

Page:32

M550/M551 Level 3 Service Manual

5.3b Preferred Rework Methods

Part to be Replaced: Microphone (Through-hole device)

Removal

Replacement

Insert legs of mic through holes in pcb and position as in above picture. Apply iron tip to both leg and pad and apply solder to leg. keep tip in Place for 3-5 secs to ensure solder melted evenly. Remove tip and allow to cool, then inspect and clean.

Removal Method

Microphone

For standard through-hole devices, remove any adjacent parts that are heat sensitive i.e. key pad assembly etc. Set station temperature to approx 350 degrees and select a suitable hand piece. Add flux to the solder joints with brush applicator. Tin the tip with solder and lower over the solder connection. Ensure complete solder melt and apply the vacuum whilst using a rotating motion of the hand piece. Keep the hand piece on the pad for no longer than 5 secs at any one time. Remove the mic from the joint, leaving the vacuum on for a further 3 seconds to clear molten solder from the head. Repeat for both mic pins and carefully remove device. Using fluxed solder braid and standard soldering iron, clean excess solder off pad. If no vacuum system is available then alternatively use a soldering iron.

Recommended Equipment

Continuous Vacuum De-soldering System Soldering Iron Solder Braid Flux Flux-Cored Solder (Alternative approach is 2 irons or hot tweezers for devices not suitable for a de-solder system)

Page:33

Part to be Replaced: Battery, SIM Connectors and Three Pole Audio Jack

M550/M551 Level 3 Service Manual

Three pole audio Jack

Battery Connector

SIM Connector

Removal Method

Set the heater temperature to approx 425 the device in question. Add flux to the solder joints with Boncote brush

applicator and position the air tip approx 0.5cm away from the component. Direct the hot air over the component until complete solder melt is achieved (air guides can be used where appropriate). Grasp the component with tweezers and remove from the PCB. Using a fluxed solder braid and standard soldering iron, clean excess solder off pad.

Note: If replacing the SIM connector using an hot air pencil, the antenna must first be removed. This is to prevent the hot air from damaging the plastic antenna body. Recommended Equipment

Hot Air Pencil with suitable tip. Soldering Iron Solder Braid Flux Tweezers Flux-Cored Solder

degrees and install a suitable tip for

Replacement

Set iron temperature to 350 degrees +/- 5% and ensure the iron has been on for the manufacturers recommended warm up period. Thermal shock the tip on a moist sponge and re-tin the tip. Position the component accurately to the PCB. Apply flux and tack solder two adjacent corner leads. Apply flux to the remaining leads and individually hand solder each lead in turn. Clean contacts and solder area if required. Note: Care must be taken not to damage the plastic parts of the connectors or ANY parts

located near the item being replaced.

Page:34

r

Outer Lens

Screw

(4pc)

Outer Ring

LCD

Hinge

Inner Hsg

Lens

M550/M551 Level 3 Service Manual

5.4 Mechanical Assembly Parts

RF Adaptor

fitted to battery

Battery

Holde

FPC

SIM

Front Hsg

Keypad

Metal-dome

Mic Gasket

PCBA

Screw (2pc)

Battery

Battery Cover

Part Descrtion:

1. Inner Hsg Assy:

2. Populated PCBA: Not supplied as a spare part

3. Hinge

4. Screws

5. Mic Gasket

6. LCD Assy

7. Keypad Assy

8. Metal Dome:

9. Front Housing

10. Battery Holder

11. Outer Ring

12. FPC: BOARD TO BOARD FPC

13. Lens

14. Battery Cover

15. Outer Lens

Page:35

M550/M551 Level 3 Service Manual

5.5 Dis-Assembly Procedure

5.5a Battery Holder Cover Removal

Note: Before the M550/M551 can be dis-assembled, the battery and battery cover must firstly be removed.

BU: Bottom Unit

Note: When dis-assembling the product great care must be taken while opening the covers, as they can easily be damaged if not handled correctly. Always ensure the fixing locks/hooking features are released correctly.

Insert the separator tool between BU front and the Battery holder plastics to pry open the lower end of the assy both left and right hand sides.

Remove two screws securing the Battery Holder.

Page:36

M550/M551 Level 3 Service Manual

5.5a Battery Holder Cover Removal

Continue to pry the left and right sides to working the tool further along the housing edge to release all the side locks.

Note:

To minimise damage to battery holder and front housing care must be taken not to damage the side locks/hooking features on the battery holder.

With the side locks released, the battery holder will hinge off the BU front housing.

Page:37

M550/M551 Level 3 Service Manual

5.5b PCB Removal

Keypad

Disconnect the FPC from the connector on the pcb. Always remove the FPC gently as the connector may be damaged if not handled correctly.

Now the main PCB can be removed from the front housing. The rubber keypad can also be removed from the front housing if required.

ALWAYS ENSURE THAT THE FPC IS HANDLED CORRECLTY AND IS NEVER CREASED AS THIS CAN CAUSE DAMAGE TO ITS INTERNAL LAYERS.

IMPORTANT NOTICE

Now the Mic gasket can be removed using tweezers.

Page:38

p

M550/M551 Level 3 Service Manual

5.5c Dis-assembling the top unit from the front housing

The top unit (TU) can be disconnected from the front housing as shown below.

90 deg

TU (Top Unit)

TU angled @ 90 deg relative to Front cover

Angle the unit as shown so the TU and front housing are at an angle of 90 deg. This is because the hinge assembly can only be disassembled/assembled when in this

IMPORTANT NOTICE

osition.

Push centre of hinge body in arrow direction shown in RED.

Hinge body

Spring ground contact “In Position”

Position screwdriver head here.

To separate the TU from the front housing, the hinge body must be pushed backwards through the locating hole in the front housing. Using a small flat blade screwdriver (size:3mm), position it as shown above. The head of the screwdriver should be positioned between the sprung contact and the centre of the hinge body. Care must be taken not to

damage the spring contact when pushing the hinge body backwards through the locating hole. When the hinge has been pushed through the locating hole the TU and front

housing can then be separated. While separating the TU and front housing, they must be kept at 90deg as shown above.

Page:39

M550/M551 Level 3 Service Manual

Separating the TU and front housing units.

IMPORTANT: Take care when easing the

FPC through the locating slot in front housing.

Front Housing

Locating slot

5.5d Dis-assembling the top unit 5.5d Dis-assembling the top unit

Using the opening tool as shown above carefully remove the outer lens. This will then give access to the four screws on the outer bezel.

Note: A new outer lens will have to

be fitted when assembling the unit.

TU

Remove the four fixing screws.

Page:40

M550/M551 Level 3 Service Manual

5.5d Dis-assembling the top unit

Carefully insert the opening tool between the outer ring and inner housing as shown above. Slide the tool down the length of the joint on both sides and gently ease the parts apart.

Before fully separating the outer bezel from the inner housing carefully slide the bezel in the direction shown. This is so to release the hook features located on the inner housing from the bezel.

IMPORTANT: Take care when dis-assembling

the bezel and housing as they can be damaged if not opened in the correct way.

5.5e Removing the LCD assembly from the inner housing

LCD Assy

Disconnecting the FPC

Using the opening tool gently insert the one end between the LCD assy and FPC connector as shown. Then prise the connector away from the LCD assy to disconnect it.

Disconnecting the FPC

Now the FPC can be removed via the slot in the inner housing.

IMPORTANT: Take care not to snag the

FPC or its connector on the inner housing when removing it.

Page:41

y

A

r

Disconnecting Vibrator, Earpiece+ Polyphonic speaker assembly

Again using the opening tool gently insert the one end between the base of the vibrator body and inner housing as shown. Then gently prise the vibrator away from the housing to remove it. The same method can be used to remove the earpiece/speaker unit. Once these parts have been disconnected from the inner housing the LCD module can then be removed. IMPORTANT: Always use gloves when handling the LCD

module as both LCD screens can be easil

5.5f

Replacing the vibrator and earpiece + polyphonic speaker assembly

dhesive backing tape*

E/P+P-Spkr

Remove resin encapsulate

Vibrator

M550/M551 Level 3 Service Manual

Earpiece+P-Speaker

scratched/damaged.

Vibrato

With the LCD module removed from the inner housing both the vibrator and speaker assembly must be de-soldered before removal. Only replace the vibrator/speakers if faulty. The LCD module can also be replaced separately to the vibrator or speakers if required.

IMPORTANT

Before these parts can be de-soldered, the protective resin, which covers the wires needs to be removed. The resin can be removed by using tweezers to carefully detach it from the LCD pcb.

* Replacement vibrator and speaker units are supplied with an adhesive backing tape used for fixing them to the inner housing. Always replace the backing tape if the parts are detached from the housing.

Page:42

1

M550/M551 Level 3 Service Manual

5.6 Assembly Procedure

Assembly of the M550/551 is the reverse of the dis-assembly procedure, except for the following care points.

5.6a Removing/Replacing the hinge assembly

Gnd Contact point with hinge

Gnd Contact

Hinge Assy

Resistance measurement points: <1 ohm

The hinge can be removed either by hand or tweezers, by gently pulling it out from the cavity on the inner housing in the direction shown in red. When re-fitting the hinge push fit back into the cavity in the reverse direction, ensuring it is fully located in position.

IMPORTANT:

Whenever the hinge is removed and re-fitted a resistance measurement must be taken to ensure that there is good electrical continuity between the ground contact (shown above) and the centre of the hinge. Using a digital multi-meter measure at the points shown above. The value measured should be < 1ohm. If this value is >1 ohm, then check/clean hinge body and inspect the end of the ground contact where it connects to the hinge body.

5.6b Refitting the LCD module (including the vibrator/speaker assy)

Vibrator Fitting

2

1) Refit the FPC onto the LCD module. Then Align the Vibrator with the location feature on inner housing. Ensure that the wires do not become trapped under the LCD module.

2) Manoeuvre the LCD module toward Left hand side of inner housing and guide the FPC through the slot feature in the housing as shown above.

IMPORTANT: always ensure the adhesive backing tape is removed from the vibrator/speaker

assy before they are placed in position on the inner housing. Also check that the FPC is not bent or creased before assembly.

Page:43

12 3

2

3

A

1

M550/M551 Level 3 Service Manual

Speaker Assy and LCD Fitting

Use tweezers dress wires fold back the speaker over the LCD module - remo adhesive backing.

IMPORTANT:

The FPC is fragile and should under no circumstances be allowed to crease. Take care not to trap the Vibrator or earpiece wires during assy. Avoid applying excessive pressure on the earpiece gauze.

ALWAYS observe anti static precautions when handling the PCB or LCD Assy.

Assembling the Top unit (TU) to the Bottom unit (BU)

ve

Turn the speaker through 180 degs so the adhesive is face down – then rotate in direction indicated.

Gently press earpiece into front housing and dress wires between the vibrator and speaker.

RH Hinge pivot

Slot feature

Align the FPC with the slot feature on the BU Front housing. Carefully pass the FPC through the slot. Slide the TU assy over the BU front housing hinge cover to mate with the RH hinge pivot .

Push Hinge down

Push here

Use the opening tool to depress the spring loaded hinge - press down as shown. Then push the BU (in direction/location shown) towards the TU so the hinge engages in position in the BU.

The spring loaded hinge will finally self centre when the module flip is fully opened.

positive engagement lock will be observed when the TU assy is rotated as shown.

IMPORTANT

Test the flip operates smoothly - no abnormal clicking noise or stiffness.

Page:44

A

g

Fitting the Battery Holder to the Bottom unit

Cantilever Lock

Hook Feature

The assembly sequence and method are important to avoid scrap or rework. Angle the battery holder onto the BU front housing as shown above. Slide into position the two hook features left and right and one centre cantilever lock .

M550/M551 Level 3 Service Manual

Snap fit the 5 lock features on the battery holder by pressing where shown above.

Replacing the Metal dome Key sheet

Finally press fit the upper lock features where indicated above. The two fixing screws can then be fitted.

MPORTANT

Check that all the clips have fully engaged. Also Check that the FPC does not protrude from the assembled housings.

Carefully remove the original metal dome. Inspect the pcb contacts and ensure surface is free from contamination and dust.

Clean the pcb contact pads with the gold guard pen to ensure they are clean.

Backlight cut outs

lign along pcb edge.

Peel the protective backing from the new metal dome sheet. Align the sheet with the edge of the pcb and cut outs for the LED backli

hts.

Smooth over dome sheet with fingers to ensure it is fully adhered to the pcb. Also check that the metal domes are aligned with the keypad contacts on the pcb.

Page:45

M550/M551 Level 3 Service Manual

Section 6

Troubleshooting Guide

Page:46

M550/M551 Level 3 Service Manual

Important!

Please read the following cautions, notes and

warnings before progressing through this

manual or undertaking any repair action.

Remember: SAFETY FIRST!

Part 6a. General troubleshooting

Troubleshooting:

Customers appreciate people with good product knowledge and someone who can solve any problems quickly and conveniently.

Read each of the tips below to find out how to solve the most common problems that some customers experience.

We suggest you also print a copy of the troubleshooting guide in the user manual, which together will enable you to solve most customers problems immediately

Customer Issues

Phone does not switch on…

Wipe clean the battery contacts on the phone and on the battery itself. Try a battery from a working phone. If the phone powers on OK, the problem may be that the battery is not charging so refer to the next topic for some tips on checking charging problems

Phone will not charge…

The charging function can be confirmed by inserting a known good charger into the phone. Wait for at least ten minutes for the charging icon to appear. You can also connect the customers’ charger to a known working phone. If the phone does not charge, the charger will need to be replaced.

Battery does not Last…

The standby time and talk time figures that are quoted in our sales literature are made according to strict industry standards that give the best possible guide to battery performance and product comparisons. Many factors in the customers own day-to-day use of the phone effect the actual battery life. Sending text messages or playing games activates the display backlights, which greatly affect the battery life. Another example is the areas network coverage. A strong network signal uses significantly less battery power from the phone than a weaker network signal.

Page:47

M550/M551 Level 3 Service Manual

It is also important to remember the relationship between standby times and talk time. As a rough guide, for every minute the phone is in a call, the standby time remaining reduces by two hours. Other tips to get the most battery life out of the phone are to ensure the battery is charged for at least 12 hours before using the phone for the first time, and customers should occasionally allow their battery to fully discharge until the phone switches itself off, before recharging it.

No signal or Network…

Try another SIM card in the phone. If the network name appears on the display, the customer may have an invalid SIM card, and should contact their service provider.

Can’t make/receive calls…

Make a live call in-store. If there is no connection at all, try another SIM card. If calls can then be made OK, the customer may have an invalid SIM or call barring is enabled, and the customer will need to contact their service provider. If calls in-store are OK, the customer may be experiencing network congestion at certain times of the day, or limited coverage in certain areas.

Customer Fault Codes

There are 21 fault codes, which are used to record the reported fault from the customer, please see them listed below. Under each fault codes are some general troubleshooting tips, which may help you determine the cause of the problem. If these do not rectify the problem then further detailed inspection and fault finding will be required. There are detailed circuit descriptions and debug techniques described in parts “ 6b Base band troubleshooting” and “6c RF troubleshooting”.

1 Liquid Damage/ Corrosion 2 Cosmetic 3 No Signal 4 Drops calls / Poor Rx Tx 5 Display Fault- Blank – Monochrome screen 6 Display fault- lines missing-Monochrome screen 7 Backlight 8 Keys not functioning

9 Power On / Off Faults 10 Charging Fault 11 Audio Fault 12 SIM Reader Fault 13 Software Fault 14 Battery Fault 15 No Fault Found 16 Vibrator Fault 17 Buzzer (ring tone) fault 18 Other 19 Display Fault-Blank – Colour screen 20 Display Fault- Lines missing – Colour screen 21 Hinge / Flip problem

The 21 Reported fault codes

Page:48

(

)

A

M550/M551 Level 3 Service Manual

1 ) Liquid Damage

Check for water/liquid ingress around the following areas, keypad, charging jack, SIM connector, battery contacts, LCD module and also the PCB. Any liquid ingress found will instantly void the Sendo warranty that is given with a Sendo product. Please find attached picture for example of liquid ingress.

Note

ALWAYS CHECK BOTH THE BOTTOM PCB AND LCD MODULE FOR LIQUID CONTAMINATION AS THIS INVALIDATES THE WARRANTY OF THE PRODUCT.

2) Cosmetic

Cosmetic damage/ scratches to a Sendo product are NOT covered by a warranty that is given with a Sendo produ

ct.

3) No Signal/Network

If a Sendo phone is returned with ‘ No Signal’, the first test should be to put a test SIM card into the phone and complete some call testing on test equipment to determine whether or not the phone is able to make/receive a call. If the phone is unable to get a signal then both the antenna and its soldering should be inspected. Also clean/check the RF switch “X501”(see picture). Also check the condition of the grounding contacts in both the

RF Switch

X501

top unit and bottom unit. (See pictures on next page for details

).

ntenna Solder point

Page:49

Check sprung grounding contacts.

4) Drops Calls / Poor Rx/Tx

Place test SIM card into phone and complete GSM tests on test equipment, this will evaluate phone to see if phone is operating within GSM spec. If unit fails check the antenna/X501 as above. Also check the antenna grounding contacts. Only Level 3 centres will be able to adjust RF settings.

Checking Antenna Grounding Contacts

M550/M551 Level 3 Service Manual

B

A

To ensure that the ground contacts are making good contact check the resistance between point A-B. The Resistance should be less <1ohm. If > 1ohm then check:

1) All grounding contacts (circled) for condition/damage.

2) Clean all contacts including contact pad on lower pcb.

3) Check/clean hinge body.

M550/M551 Doc SP11498 Rev:01 Aug03

Page:50

M550/M551 Level 3 Service Manual

5) Display Fault

Blank Display

If either the outer or inner LCD’s are blank, then check:

IMPORTANT: LCD Damage: Inspect both LCD’s for physical damage. If LCD

shows signs of physical damage (see picture) then the Sendo warranty is void for this repair.

If there is no sign of physical damage then try the following:-

4) FPC: Inspect the FPC connection at both ends. Ensure that the FPC is seated in its socket and that the foam retaining pad is in position on inner housing. Also check the condition of the FPC itself for damage or any obvious signs of failure – especially check for cracks in the FPC and the soldering of the connector plugs.

5) Cleaning: Before replacing any parts try cleaning the FPC connector/ sockets with a suitable cleaning agent.

6) FPC/LCD: Try connecting another “good” one to prove if the FPC is the cause of the fault. If the FPC is ok, then try connecting another LCD module to establish whether the original module is faulty.

LCD Damage

Foam Retaining Pad (In correct Position)

Lcd damage

FPC

Check: FPC Condition

• Connectors

• Flexi

Page:51

M550/M551 Level 3 Service Manual

Check: FPC/Connection/Clean

6) Display Fault

missing Lines on display

If either the outer or inner LCD’s are blank, then check:

If there is no sign of physical damage then try the following:-

1) FPC: Inspect the FPC connection at both ends. Ensure that the FPC is seated in its socket and that the foam retaining pad is in position on inner housing. Also check the condition of the FPC itself for damage or any obvious signs of failure – especially check for cracks in the FPC and the soldering of the connector plugs.

2) Cleaning: Before replacing any parts try cleaning the FPC connector/ sockets with a suitable cleaning agent.

3) FPC/LCD: Try connecting another “good” one to prove if the FPC is the cause of the fault. If the FPC is ok, then try connecting another LCD module to establish whether the original module is faulty.

Note:

The LCD module IS NOT a repairable item and must only be replaced. NEVER rework it or attempt to repair it. FAULTY LCD MODULES MUST BE QUARANTINED ON BEHALF OF SENDO.

Missing lines on inner display

Page:52

f

7) Backlight.

Things to check:

1) Check whether backlight LED’s are working and i soldering is ok. Replace/resolder faulty LED if required.

2) Inspect the soldering (circled red) for defects as these are the backlight drive circuit area’s.

M550/M551 Level 3 Service Manual

8) Keys Not Functioning.

Things to check: Check polydomes on keypad (see picture). Check keyboard contacts on main PCB. Clean contacts if required.

Keypad Area

Page:53

M550/M551 Level 3 Service Manual

9) Power On/Offs faults.

Check battery voltage and condition of contacts on battery.

Test the phone on battery eliminator (see picture), see if fault occurs. If fault occurs then check/clean battery connector (X400) soldering and also contacts.

X400 – Battery connector

10) Charging Fault

Check that the Battery isn’t causing the problem.

Make sure the Charger Connector (circled) is not damaged/faulty and there is not a dry joint on any of the solder points, if this is the case re-solder all of them when repairing the fault.

Check the battery contacts to make sure there is a connection to the battery

Check the circled area’s on the pcb for soldering defects.

Solder Points

Check soldering

Page:54

g

11) Audio Fault

Check both the Speaker and Mic for dry joints or obvious damage. On Speaker especially check that its wires are not broken or damaged. Check FPC condition and both the connectors are clean and soldering is good. Check PCB components (circled) for visual dama

e and soldering defects.

12) SIM Reader Fault

Clean the SIM contacts and check for soldering defects on the X402 SIM reader. Check components circled above. Ensure the connection pins on X402 are not bent or broken. Also ensure that the front housing and battery holder are clipped together correctly as the SIM card will not be retained against the contacts if the covers are not fitted together.

M550/M551 Level 3 Service Manual

Audio components

Check FPC/X403

Page:55

13) Software Fault

Please update any unit to the latest version on Software

The Software updates will be issued to the service centres via mail or Internet. There will be a technical bulletin with each issue.

Software upgrade will also default the unit back to factory configuration settings. Sometime the customer will adjust the phone and think they have caused a fault. (Please re-software these units to reset them)

Units which have ‘BLOCKED’ show, check the following:-

- check the handset has an IMEI, this can be done

- If the unit has a IMEI, then the unit is blocked

14) Battery Fault

Check that the voltage in the battery is above 3.3V, if not then put the battery on charge for an hour to see if it rises and the phone charge indicator lights up

Check for corrosion and damage to the battery

Ensure the battery contacts on the phone are not faulty or dirty.

NOTE: To ensure professional battery testing please use an astrotec battery checker ( Info from Sendo )

by typing *#06#, the IMEI will be shown on the screen, if it has *?????????????, then send it to a Level 3 repair center.

because the NCK code was typed in wrong more than 6-12 times, re-software the phone will reset the counters, NOT unlock the phone

Astratec “Expresscheck” battery tester http://www.astratec.co.uk

M550/M551 Level 3 Service Manual

Page:56

15) No Fault Found (NFF)

Most NFF can be down to the Network Service Quality in the location where customer live, Also units can wrongly be diagnosed and NFF can be made of a variety of returns

Please ensure that the Service Centres carries out the following tests on a NFF

- Checks the modules radio performance, with making live calls on the customers

- The phones menu functions are tested to ensure that the phone runs without

- The phone is quality checked, by powering on/off various times, checking network

16) Vibrator

Check in the user menus that the vibrator option is selected to ON, some operators may have this switched off fo factory s

Check the connection wires to the vibrator are good and the soldering is ok.

Ensure that the contacts are not damaged or bent and are clean

Check the vibrator works by changing it with a know good one, Level 3 service centre can put a voltage load across it to check it works

17) Buzzer (ring tone) fault

Ensure that the user has not muted the buzzer in the phones menu

Check the Buzzer has not been damaged, Make sure that there are no dry joints on the contacts and there is nothing blocking the buzzer output in the case and cover of the phone

network (GSM test set)

problems

connection, ringer and audio.

et

ting

M550/M551 Level 3 Service Manual

Vibrator Checks:

1) Connection wires

2) Soldering of joints

r

3) PFC/X403 connector

4) Try another known good vibrator to verify if it is faulty or the LCD module.

Buzzer Checks:

1) Connection wires

2) Soldering of joints

3) PFC/X403 connector

4) Try another known good buzzer to verify if it is faulty or the LCD module.

Page: 57 M550/M551 Level 3 Service Manual

6b Base band Circuit Description and De-bug

FUNCTIONAL BLOCK DIAGRAM OF CORAL

M550 is a ‘clam shell’ phone. There are two pieces of pcbs in M550. The main baseband and RF circuitries are on the main pcb assembly while the LCD module assembly is on the lcd pcb. The following diagram illustrates the functional blocks located on the two pcb assemblies.

Page: 58 M550/M551 Level 3 Service Manual

t

r

A

pag

Audio Description

Please refer to the circuit below and on pages 2,4 Schematic; 8J60-0M000-02000-SCH. BB_EARP and BB_EARN are the positive and negative differential inputs to the internal speaker fitted to the LCD module. When the handsfree connector is inserted BB_AUX_MIC detects the insertion by the impedance change. This is detected by IC200 on pin C7 (BB_AUX_MIC). This is line will change state and hence the audio route will change. X200 is the audio jack. Pin 3 is the audio output from IC200 and pin 2 is the audio in. X404 is the microphone. Its two outputs are BB_MICP and BB_MICN. These differential outputs are fed to the Iota chip on pins J7, H7. The biasing for the microphone is from AVDD_MIC (which is derived from BB_MIC_REF_P, from IC200-#J8), and is only present during a call or loop back. Between the voice band serial port in IC200 and the IC100, we have the data link. The four lines are BB_VCLK, BB_VFS, BB_VDX, and BB_VDR. VCLK is the voice band serial port clock. The other three are the SPI bus and are Voice band serial Frame Synchronisation (VFS), Voice band serial port Data Transmit (VDX), and Voice band Data Receive (VDR).

Aux-Mic call control

When a Headset is fitted into system connector, BB_AUX_MIC is pulled low. Iota (IC200 #C7) samples it on inpu ADIN3. This ADC input is linked to IO connector X200 pin 2 via R208. It is pulled high by the mic-bias potential. (Afte

MIC_REF_P passes through R406, it is named AVDD_MIC.

Note: A block schematic diagram showing the related audio, SIM reader and audio jack circuits can be found in:

“Section 4. Part a: Audio Circuits and SIM Interface”

udio Out from IC200

#K9 to X200 jack

udio In from Mic to (IC200

#H7-J7)

BB_AUX_MIC

To: IC200 #C7. Pulled low when headset connected.

Not used

udio input from microphone X404. See next

Charger input: 5v.d.c

X200-Audio jack

To X403 connector (#25-27) and then earpiece.

e.

Page: 59 M550/M551 Level 3 Service Manual

A

o

o IC100 #

r

Biasing voltage for Microphone – IC200 #J8.

udio In from Mic (X404) to (IC200

#H7-J7)

IC407 is the device which generates the ring tones on M550/M551. It can generate up to 16 voices with different tones. It contains a decorder and FM synthesiser. IC407 also contains an amplifier with an output of around 500mW. The 13Mhz clock is used as the master clock for the PLL inside IC407. Data from IC100 is from the parallel bus along lines D0-D7. There are also RnW,Chip Select, and Clock lines from IC100 to control the data transmission. The signal VIBR_EN from IC407 pin19 goes high to enable the vibrator. The vibrator is located inside the upper plastics with its drive circuits. VIBR_EN is connected to the vibrator via X403 pin22.

Data Lines from IC100

m IC409 #3

Fr

From IC100 #D3,M4,E2

m IC100 #F12

Fr

T

Microphone Circuit

(Voltage supply to X200 – Jack socket circuit)

X404 -Mic

IC407 - Ring tone generator and Vibrator control IC

To X403 connecto

Not used

IC407

Not used

P1

From IC100 #P8

Page: 60 M550/M551 Level 3 Service Manual

Keyboard and LCD Backlight Control

Backlight Operation

To operate the backlights,IC100-#L7 takes the control line KB_BKLT_EN high. KB_BKLT_EN will switch T400 on allowing the current to flow through the diodes. The diodes are supplied using LCD_VBKLT (supplied from LCD display via X403 - #12). The current output is regulated by R448/R454.

Keyboard Operation

When a key is pressed, the corresponding row and column lines are shorted together. To allow key press detection, all input pins (KB_ROW) are pulled up to VCC and all output pins (KB_COL) are driven to a low state. Any activation of a key will short together the corresponding column and row address lines and form an interrupt within IC100, which constantly scans these lines to detect a key press.

LCD_VBKLT – from X403 #12

KB_BKLT_EN–from IC100 # L7

Page: 61 M550/M551 Level 3 Service Manual

On/Off Power Key – Pulsed low when key pressed

To IC100 # K5-P5

To IC200 “IOTA” #F8

M550 Power up Sequence and power supplies

1. When the battery is connected “VBAT” is applied to the board from the battery.

2. When the power key is pressed “PWR_ON” is taken low temporarily,

Then IC200 generates the following power supplies:VCORE 1.8VDC TP202 VIO 2.8VDC TP200 VMEMORY 2.8VDC TP205 AVDD 2.8VDC TP203 VUPR Approx. VBATR237 IBIAS 1.2VDC R205 VMEMRAM 2.8VDC TP210 VREF 1.2VDC C225 VRTC_IOTA C255

3. The 32KHz clock (X102) will now start, measured at C110/C111

4. Control line BB_nRESET, from (IC200) IOTA (TP206) goes high, taking calypso (IC100) out of reset.

5. Control line BB_ON_NOFF, from IOTA (#-E3) to Calypso (#-F10) goes high. (TP109)

6. Now Calypso will enable the radio circuits:

7. Calypso takes RF_REF_ON (C502, IC501 pin 3), high. This turns on radio regulators.

From IC100 # K6-P6

Page: 62 M550/M551 Level 3 Service Manual

8. The 13MHz Oscillator (IC603) now generates the 13MHz signal, which is fed to the Calypso (#-E13). The signal “RF_CLK13M” is then passed from the calypso (IC100-#F12) to the Iota (IC200-E4).

9. The calypso is now executing code from memory, and the backlight LED’s should illuminate.

Note. The Flash Part is a 64Mbit (8Mbyte) Flash with a 4Mbit SRAM attachment.

Additional power supply “VCC_2V8_RF” for RF circuits generated by IC501

Signal “LB_nOPC” (from IC100-#A13) “Calypso” enables IC501.

Power supplies generated by IC200 “IOTA”

IC200 “IOTA”

IC501 – 2.85v Power supply for RF circuitry

Page: 63 M550/M551 Level 3 Service Manual

Power supply and control signal interconnection table

Page: 64

M550/M551 Level 3 Service Manual

Probing Test-Point (side 1)

AVDD

2.8V

VIO

2.8V

VMEMRAM_IOTA

2.8V

VCORE

1.8V

VMEMORY_IOTA

2.8V

BB_ON_nOFF

Check HIGH “1” to

enable RADIO

BB_nRESET

High “1” when

IC200 is OK

Page: 65

M550/M551 Level 3 Service Manual

Probing Test-Point (side 2)

RF_REF_ON

High “1”

VREF

1.2VDC

13 MHz Crystal

Master Clock

32 KHz (RTC)

Real Time

Clock

IBIA

1.2VDC

VUPR

VBATT 3.7V

VRTC_IOTA

1.5 V

Page: 66 M550/M551 Level 3 Service Manual

SIM INTERFACE

The SIM Card circuitry first comprises of a four wire parallel interface between the SIM Card holder (X402) and the IOTA (IC200). The four lines comprise of the following: The power supply SIM_VCC (X402, 1-IC200, B4), the reset line SIM_RST (X402, 2-IC200, D4), the clock line SIM_CLK (X402, 3-IC200, C4) and the serial data line SIM_IO (X402, 6-IC200, B3). X400, 4 is grounded. The SIM_IO is biased by SIM_VCC via R425. There are also three signals between Calypso (IC100) and Iota (IC200). These are BB_SIM_RST (IC100, G10-IC200, G4), BB_SIM_CLK (IC100, F13-IC200, F4) and BB_SIM_IO (IC100, G13-IC200, E5).

SIM circuit block diagram

VIO

IC100

BB_SIM_IO

BB_SIM_CLK

BB_SIM_RST

IC200

SIM_IO

SIM_CLK

SIM_RST

SIM_VCC

IO VDD

CLK X402

RST

SIM circuit diagram

Page: 67 M550/M551 Level 3 Service Manual

Battery charging interface

The main function of the Charger interface within (IC200) is the charging control of the M550’s Li-ion Battery. The battery monitoring uses the 10 bit ADC converter within IC200 to measure the battery voltage, battery temperature, battery type, battery charge current, battery charger input voltage. IC200 uses approximately 1.2V, (found on C225), for its reference, so if this is incorrect, ADC readings may fail. Another voltage indicates Iota current reference, found on R205. Expect 1.2V here. The magnitude of the charging current is set by the 10 bits of a programming register converted by an 10 bit Digital to Analog Converter, whose output sets the reference input of the charging current control loop. The battery charger interface performs also some auxiliary functions. The battery charger interface is under registers control.

Battery charging control

VCHARGE is the charge voltage from the battery charger. R200 pulls down the VCHARGE line when there is no charge voltage on the line. ICTL from IC200 controls the charge rate. ICTL controls T200, it determines the level of bias through the P channel MOSFET inside T200. By controlling the bias conditions, it controls the rate at which VCHARGE can charge VBATT_BB. For Li-Ion battery’s only, when VBATT_BB reaches 4.2V the charger circuit will switch to trickle charge. When ICTL is low, the charge current will be high and when ICTL is high, then the charge current will be low (trickle). The phones LCD will no longer indicate charging. For the Ni-MH/Ni-Cd, the battery charging scheme is constant current only, charging is stopped when Delta-V across battery terminals versus time inverts from positive to slightly negative. The charging device is low output impedance DC voltage source of 6.2V (can accept up to 6.8V). T200 contains a power Schottky diode connected between pin VCHG and pin VBATT2 of IOTA. The role of the Schottky diode is to prevent reverse leakage current from the main battery in case the charging device is connected to the mobile without delivering any voltage at its output.

Input: 5vdc (300ma) from charger to “X200” audio jack.

To “VCHARGE”–T200

Charge flow

ICTL = “0”-T200 “On”

Page: 68 M550/M551 Level 3 Service Manual

Display

DISPLAY BUS

IC405

IC405 is designed for asynchronous communication between data buses. The device transmits data from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (nFOE) input. The output-enable (OE) input can be used to disable the device so the buses are effectively isolated. When V the device is in the high impedance state during power up or power down. The I disables the outputs, preventing damaging current backflow through the device when it is powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.

INPUTS

OE nFOE

L L DATA FROM BUS B TO A L H DATA FROM BUS B TO A

H X ISOLATION

OPERATION

CC is between 0 and 1.5 V,

off circuitry

IC406

IC406 is a single line driver with a 3-state output. The output is disabled when the outputenable (OE) input is high. This device is fully specified for partial-power-down applications using I through the device when it is powered down.

off. The Ioff circuitry disables the outputs, preventing damaging current backflow

INPUTS

OE nFOE

L H H L L L

H X ISOLATION

OPERATION

BASEBAND DEBUG GUIDE

POWER UP PROBLEMS

If a unit will not power up then this could be caused by a number of things. One of the first steps is to try and reload the phone software into the unit. Please follow the steps described in “Section 7 – Software Download”. If the unit does still not powewr up ok then ensure that all power supplies and system clocks are functioning. First apply 4.2 volts to the unit and press the power key and check that the following signals are present and correct:-.

SIGNAL LOCATION INFORMATION 1 BB_nRESET TP206 High when Iota is ‘OK

& ready’ 2 VCORE TP202 3 VIO TP200 4 AVDD TP203 5 OSC32K_OUT C110/C111 32768Hz Real Time

Clock

BB_CLK13M

6

(VCXO_13MHZ)

7 VBATT C257/C260

C116 (NC) 13MHzMaster Clock

Page: 69 M550/M551 Level 3 Service Manual

8 BB_ON_nOFF TP109 From Iota, enabling

Calypso 9 RF_REF_ON C502 (NC)/

IC501 (3)

From Calypso,

enabling 13Mhz in RF

It could also be useful to measure the following points:

NAME LOCATION EXPECTED INFORMATION 1 IBIAS R205 1.2VDC Reference current 2 VREF C225 1.2VDC Reference voltage 3 VUPR C240 VBATT Uninterruptible Power Rail 4 VRTC_IOTA C255 1.5V 1.35-1.65Vdc 5 VMEMRAM_IOTA TP210 2.8V 6 VMEMORY_IOTA TP205 2.8V Flash power supply 7 AVDD TP203 2.8V 8 nCSO DP104 9 nFOE DP103 10 RnW DP101

Possible Causes for No power up

• No power supplies from Iota:

If the voltages in the table on the previous page are all ok, Check BB_nRESET and BB_ON_NOFF are both high.

• If these are ok then check the clocks:

32KHz or 13MHz clock not running: Check if the 32KHz crystal is badly soldered. Check if the capacitors connected to the crystal are badly soldered. Calypsos could be badly soldered. Calypsos could be too hot, after rework Calypsos could have liquid solvent under it, after cleaning. This needs to evaporate.

If 32KHz is ok, then check 13MHZ

Check if RF_REF_ON is high Check radio power supply from regulator IC501 is 2.8VDC (VCC_2V8_RF, TP500). Check 13MHz oscillator and associated components.

SIM CARD CONTROL

Although the MS can communicate with both 3V & 1.8V SIM cards, they are tested here at 3V. Expected SIM activity can be measured after installing a SIM card and powering up the unit. Probing the SIM circuit at the locations described below should locate the point of failure or problem. Three signals start from Calypso, and go to Iota. These are BB_SIM_RST, BB_SIM_CLK, and BB_SIM_IO. From the Iota, four SIM signals are to SIM connector X402. These are SIM_VCC, SIM_RST, SIM_CLK, and SIM_IO

Components involved: Calypso, Iota, R122, C415, C416, C418, C419, R425 and X402

Page: 70 M550/M551 Level 3 Service Manual

If activity gets to SIM connector X402 but test still fails, check that X402 is well soldered, especially the ground pin, and contacts are clean and not bent.

If SIM activity is not seen at all, then suspect Calypso to be badly soldered / faulty.

SIGNAL LOCATION BB_SIM_RST BB_SIM_CLK BB_SIM_IO R122 SIMRST X402 (2) SIM_CLK X402 (3) SIM_VCC C207, X402 (1) SIM_IO X402 (6)

VIBRATOR CONTROL

There is limited test for the vibrator circuit. Select the vibrator option in the user menu to enable the vibrator. Check on X403 pin22/ C473. If this appears to work correctly check X403 for solder quality then replace the plastics housing the vibrator.

KEYBOARD/ LCD BACKLIGHT

Check the following signals under conditions shown. For single LED fails suspect defective LED’s or placement.

LOCATION ORIGINATOR LED’s ON LED’s OFF KB_BKLT_EN C440 (NC) IC100 (L7) HI LO T400 (3) R454/R448 T400 (3) LO HI LED BKLT D402-5 D407-

HI HI

10

Ensure each LED is operating.

Components involved: IC100, T400, R448, R454, D402-405, D407-D410.

PWR_ON KEY

Components used: Calypso, Key Pad Row (0), and PWR_ON.

Measure voltage at Calypso side of on key pattern. Confirm it goes low when PWR_ON is shorted to ground. Note that the PWR_ON may be working, (because it can ‘cancel’ displayed LCD menu selections). However if the Iota is faulty, (for instance), Calypso may be unable to properly initiate a power down sequence.

AAuuxx--MMiicc CCaallll CCoonnttrrooll

When a Headset is fitted into system connector, BB_AUX_MIC is pulled low when its ‘Call Control’ button is pressed. Iota ADC samples it on input ADIN3 (IC200 pin C7). This ADC input is linked to IO connector X200 pin 2 via R208. It is pulled high by the mic-bias potential. (After MIC_REF_P passes through R406, it is named AVDD_MIC.

Page: 71 M550/M551 Level 3 Service Manual

Components involved: Iota, R208, R217, R208, R232, C230, R205, C225, C219, C235, X200.

The line must be sampled as high when not connected to ground and low when it is connected to ground. Measure the voltage on the Iota side of R208 when BB_AUX_MIC, (TP209), is first held low, and then when left unconnected. If R208 doesn’t follow BB_AUX_MIC, then trace the voltage paths to discover the fault. If R208 is giving the voltages expected, then suspect Iota.

3

RF_PA_CTL_EN 3

TX_VCO_GSM TX_VCO_DCS

RF_ QP QN IP IN

Page: 72 M550/M551 Level 3 Service Manual

6c RF Circuit Description and De-bug

TRANSMIT BLOCK DIAGRAM

GSM_PA_TX

9 1 11 0

7 6 1

25 24

VCCOUT

VRAMP

(IC200)

IC700

DCS_PA_TX

1

11

RF_AFC (IC200)

IC500 FEIC

LPF

HPF

IICC660033

÷1 DCS ÷2 GSM

IC601

LPF

∅detector

LPF

OFFSET PLL

÷

IQ UPCONVERTER

13 RF_LON 24

14 RF_LOP 23

10 IF_ LON 27

11 IF_ LOP 28

IICC220000

Reference Clock

RF PLL

IC602

IF PLL

IOP

ION

CLKP

CLKN

IICC660000

LPF

9

ANT

2

ANT

F501 M

3

VCXO_13MHZ

7

PDNB RF_TPU_DATA_OUT (SDO) RF_TPU_DATA IN (SDI)

IC100

Control Pulse from IC100

I/Q data, from IC200

Page: 73 M550/M551 Level 3 Service Manual

Transmitter Path

Upconverter and mixer IC601

Crystal Ref: 13MHz Clock IC603

LO

Technical Inputs/ Outputs

IQ Data – Positive and Negative (I)In-Phase and Positive and Negative (Q) Quadrative-Phase

is produced in the IOTA IC 200 device (BASEBAND)

Control Pulse – Digital pulses from the IC100 Calypso and IC200 IOTA controlling the timing and pulse for the channel and Switching for TX GSM/DCS and RX.

13MHz Crystal – Main Reference clock for the RF timing and Oscillators

IF – A Intermediate Frequency is mixed with a signal (IQ) to be up converted to a transmit

frequency from a LO.

LO – A Local Oscillator is a produces a range of Frequencies to be up

ccoonnvveerrtteedd wwiitthh aann IIFF FFrreeqquueennccyy ttoo pprroodduuccee aa FFrreeqquueennccyy BBaanndd..

E-GSM 900 Band – A GSM frequency band CH.975-1024 (E) 1-124 (GSM)

DCS 1800 Band – A DCS frequency band CH. 512 - 885

E-GSM 900 MHz Up-converted modulated and mixed signal

DCS 1800 MHz Up-converted modulated and mixed signal

Synthesised IC602 IF/LO frequency generator

Page: 74 M550/M551 Level 3 Service Manual

Technical Description

From the Baseband circuit, the IOTA (IC200) inputs a positive and negative in-phase signal plus a positive and negative Quadrative-phase signal to the transceiver (IC601). These signals are labelled RF_IP, RF_IN, RF_QP & RF_QN respectively.

These four TX I and Q signals are mixed in the IQ UPCONVERTER stage of the IC601. IF signals from the RF Synthesiser (IC602) are also fed into the mixer stage of the IQ UPCONVERTER. The IF LO in IF PLL of IC602 has a frequency range of 766 to 896 MHz. The IFLO is divided by 2 internally, IFLO/2 = 383- 448 normally TX IF=448 MHz.These signals are labelled IF_LOP and IF_LON. The IQ UPCONVERTER stage divides this signal to generate the quadrature LO signals for mixing. The IQ UPCONVERTER generates a single side band (SSB) IF signal which is then filtered before being applied to the Offset Phase Lock Loop (OPLL) stage also in the IC601. The signal applied is the reference input to the OPLL. Note: The IF LO in IC602 has an external inductor, L803, for the tank circuit.

The OPLL is basically a PLL driving the TXVCO inside the IC601. The VCO is centred between the DCS and PCS bands, nominally 1350 MHz. This operates on the high side for GSM TX and the low side DCS TX. The output is divided in the OPLL for the GSM bands. The OPLL contains a mixer that mixes the TX VCO signal with the RF LO signal from IC602. The RF LO signals from the RF PLL are labelled RF_LOP and RF_LON. The RF LO tank circuit has and external inductor track between pins 16,17 and 19,20. The last stage of the IC601 is a buffer amplifier to stop the PA stages pulling the TXVCO off frequency. IC601 has a nominal power level of +9dBm with a TX OPLL bandwidth of 0.9MHz.

The RF synthesiser IC602 is made up of two PLL stages. The stages are the IF PLL and RF PLL and are used as previously described. The RF PLL is used in both the transmit and receive circuit. The IF PLL is used only in the transmit circuit. The VCO’s have their centred frequency determined by the external inductors in the tank circuits as previously mentioned. The 13MHz reference signal VCXO_13MHZ is applied on pin 7 of IC602 and is used as the reference frequency for the PLL’s.

Page: 75 M550/M551 Level 3 Service Manual

g

UP Converted DCS Signal

PA Power Amplifier

Control for PA ON/OFF and GSM/DCS Channel

Amplified DCS Signal

Amplified EGSM Si

Ramp

UP Converted GSM Signal

The Power Amplifier (IC700) has a basic circuit as shown below.

The 1

RF_PA_CTL_EN

RF_RAMP_DAC

TX_VCO_DCS TX_VCO_GSM

RF_PA_CTL_EN

st

stage of the 3-stage amplifier has a fixed bias from VBATT. The last 2 stages are

VPA

H(s)

indirectly controlled by RF_RAMP_DAC on pin 6. Inside the PA, the RF_RAMP_DAC is multiplied by a factor of 2.65 and applied to the last 2 stages. The DCS RF output from IC601 is applied to the IC700 at pin 1 and the GSM on pin 7. Both inputs have discrete components for matching the PA to IC601. The signal RF_nGSM_DCS switches the TX enable signal RF_PA_CTL_EN between the DCS path and the GSM path. VBATT is permanently connected to the PA with a standby power consumption of around 10µA. The signal RF_RAMP_DAC is used to control the magnitude and shape of the transmit RF output pulse with a positive gradient starting from 200mV peaking to 1.8V at maximum output power. The amplitude is held constant during the pulse and reduces back to zero at the end of the pulse.

VPA

DCS_PA_TX EGSM_PA_TX

nal

Page: 76 M550/M551 Level 3 Service Manual

PPAA PPoowweerr OOnn SSeeqquueennccee

1. Apply VBATT

2. Apply VCC_2V8_RF

3. Apply band select RF_nGSM_DCS

4. Apply RF_PA_CTL_EN and RF_RAMP_DAC

The PA Power down sequence is the reverse of the power up.

The APC offset Voltage (APCOFF) is applied at the start and end of the ramp and is a Baseband function applied to the DAC

PPAA EEnnaabblleess

DCS GSM TRANSMIT IDLE RF_PA_CTL_EN HI HI HI LO RF_nGSM_DCS HI LO X X

The Front End IC (IC500) comprises of filters and switches between the two transmit paths (DCS & GSM) and the receive paths. The Transmit and Receive switching is controlled by two signals. They are:

RF_RX_GSM_CTL (From IC100 pin J10)

RF_TX_DCS_CTL (From IC100 pin L13)

These signals control the transistor switch (T500), which in turn switch the paths in IC500. The biasing for the transistors is from VCC_2V8_RF.

PNP buffer transistor used.

TX DCS TX GSM RX DCS RX GSM RF_RX_GSM_CTL HI HI HI HI RF_TX_DCS_CTL HI LO HI HI

Page: 77 M550/M551 Level 3 Service Manual

Antenna Signal Transmitted

RX/TX Path IC Switching Device

Control switch for EGSM /DCS Bands

The UPCONVERTED transmit frequencies DCS_PA_TX or EGSM_PA_TX or filtered and selected in the RX/TX Path IC Switching Device (IC500)

The IC500 device acts as a switch between TX/RX and also filters the EGSM/DCS bands. Feedback is also stopped between the TX and RX.

The TX switching is control between GSM and DCS by RF_TX_EGSM/DCS_CTL lines in pin 2 and 10. The TX output is then Antenna matched LCR with L501, C510 and R503. The signal is then transmitted through the Antenna.

1. SIGNAL DATA

TRANSMITTER SECTION

Description Circuit Reference Input/Output Parameters

BATTERY SUPPLY INPUT

VBATT FILTERED

POWER SUPPLY INPUT

3.3 < VBAT <4.6V Vmax 6.5 V I=1.4A max PULSED GPRS class 12, 50% duty cycle.

GSM RF OUTPUT GSM_PA_TX OUTPUT 0 <P< +34.5 dBm,

824 <F<915 MHz

DCS RF OUTPUT DCS_PA_TX OUTPUT 0 <P< +32 dBm,

1710 <F<1910 MHz TX VCO GSM BAND TX_VCO_GSM INPUT +9 dBm nominal TX VCO DCS BAND TX_VCO_DCS INPUT +8 dBm nominal POWER RAMPING RF_RAMP_DAC INPUT 0.2 – 1.8 V PA ENABLE RF_PA_CTL_EN INPUT 2.8V PA ENABLED BAND SELECT RF_nGSM_DCS INPUT 0V=GSM

2.8V= DCS

VCC_2V8_RF VREG INPUT 2.8 V SUPPLY, 10 mA

Amplified TX RF

Page: 78 M550/M551 Level 3 Service Manual

RECIEVE

IC500 Front End IC

hpf

SW

saw saw

LPF

MF501

6 7 9 10

DCS GSM

20 19 22 21

Π/2

13 RF_LON 23

12 RF_LOP 24

LPF LPF

IC601

ADC ADC

1 2 ION IOP 12 11

CLKP CLKN

100 KHz

7

Channel filter

IC600

RF_CLK_13M

DAC

RF_IP

4

RF_IN

5

RF_QP

2

RF_QN

3

RECEIVE BLOCK DIAGRAM

ANT

IC100

CALYPSO

PDNB RF_TPU_DATA_OUT (SDO)

3

RF_TPU_DATA IN (SDI)

IC602

RF PLL

7

3

IICC66003

3

Reference Clock

RF_AFC

IICC220000

D9 D10 C9 C10

PDNB RF_TPU_DATA_OUT (SDO) RF_TPU_DATA IN (SDI)

Page: 79 M550/M551 Level 3 Service Manual

GSM RX

Signal

RX/TX Path IC Switching

RECEIVE PATH

The Antenna is part of the plastic module. A coaxial RF test point TP702 is provided on the PCB.

Filtered RX signals (band)

The Front End IC (IC500) comprises of filters and switches between the two transmit paths (DCS & GSM) and the receive paths. The Transmit and Receive switching is controlled by two signals. They are:

RF_RX_GSM_CTL (From IC100 pin J10)

RF_TX_DCS_CTL (From IC100 pin L13)

These signals control the transistor switch (T500), which in turn switch the paths in IC700. The biasing for the transistors is from VCC_2V8_RF.

TX DCS TX GSM RX DCS RX GSM RF_RX_GSM_CTL HI HI HI LO RF_TX_DCS_CTL HI LO HI HI

Page: 80 M550/M551 Level 3 Service Manual

Control Pulse to IC100

Downconverter and mixer IC601

I/Q data, to IC200

LO

Crystal Ref: 13MHz Clock IC603

RX Signal

From the FEIC (IC500) there are the two band signals named GSM_RX1 RX2, and DCS_RX1 RX2. Before these RF signals reach the transceiver chip (IC601), there are two sets of matching circuits L600-L601 and C607, C611, C613 and C614. The first stage in IC601 is the LNA stage. The matching between the LNA’s and IC500 is critical, as any mismatch will deteriorate the noise figure affecting the BER performance.

After the LNA stage the inputs are applied to a DOWNCONVERTER stage. The downconverter uses the RF LO input from the RF Synthesiser (IC602) to mix down the inputs. The RF LO from the IC602 (pins 23,24) are labelled RF_LOP, RF_LON. The RF LO is also used in the transmit circuit. The RF LO range is 1737.8MHz-1989.9MHz. For GSM, the RF LO signal is halved inside the IC601. The output from the downconverter is passed through an LPF to remove harmonics and amplified by a programmable gain amp (PGA).

The IF signal is then digitised through an ADC. The outputs from IC601 (pins 1,2) are labelled ION and IOP. The signals are on a 100KHz carrier. IOP and ION are applied to pins (11,12) on the Baseband interface chip (IC600). IOP and ION are then down converted in IC600 be mixing the signals with a 100KHz quadrature LO signal from inside IC600. A PGA amplifies the signals before being applied to a DAC. The outputs from the DAC’s are RF_IP, RF_IN, RF_QP and RF_QN on pins 2-5 of IC600. These signals are then fed to the Baseband circuit (IC200).

Note: As with the transmit circuit, the RF PLL in IC602 uses the 13MHz signal from the reference clock IC603.

Page: 81 M550/M551 Level 3 Service Manual

RReecceeiivvee ggaaiinn sseettttiinnggss ((AAGGCC))

The receive gain is adjusted to control the signal amplitudes at the IC600 DAC outputs and ADC inputs. The LNA gain is controlled with the LNAG[1:0] and LNAC[1:0] bits, the analog PGA gain is controlled with the AGAIN[2:0] bits, and the digital PGA gain is controlled with the DGAIN[5:0] bits in register 05h. The full scale of the IC600 DAC’s is controlled with the DACFS[1:0] bits in register 12h.

IICC220000

The baseband downlink path includes two identical circuits for processing the analogue baseband I and Q components generated by the RF circuits. First stage of the downlink path is a continuous-time second-order anti-aliasing filter that prevents aliasing of out of band frequency components due to sampling in the ADC. This filter serves also as an adaptation stage between external-world and on-chip circuitry. The anti-aliasing filter is followed by a third-order sigma-delta modulator that performs A/D conversion at a sampling rate of 6.5 MHz. The ADC provides 3-bit words that are fed to a digital filter that performs the decimation by a ration of 24 to lower the sampling rate to 270.8 KHz and the channel separation by providing enough rejection of the adjacent channels to allow the demodulation performances required by the GSM specification.

M550 TRANSCEIVER DEBUG

The following debug guide is written to show the RF Receive/Transmit Stage. The RF inputs and outputs levels are given as approximate levels. Each stage also includes the enables plus other essential signals.

The receive path measurements were taken with an RF input signal of -65 dBm in strength and on channel 62 GSM, 698 DCS.

The transmit path measurements were made using a phased phone on channel 62 GSM, 698 DCS power step 00

RECEIVER ADJUSTMENT

This receiver calibration makes sure that the transceiver reports the correct signal level to within ± 0.5dbm. The input signal to the transceiver is -90dbm on CH 62 (947.4mhz ±67khz) the gain range of the VGA (voltage gain adjustment) amplifier is 0 to 63 db and is altered until the reported signal level is within specification.

If the transceiver failed during calibration, try to calibrate it manually on the bench using sate.

• Select the radio page in sate.

• Set your signal generator to 947.467 (GSM CH62) at –65dbm. Remember to take

cable loss and impedance mismatch of the probe into account.

• Place the board into the PCB fixture.

• Connect the cable from the fixture to the signal generator.

• Power up the board and select start Rx, in the sate window.

At the bottom of the sate page, the reported signal level is shown. If it does not report back – 90 ± 0.5dbm try changing the AGC to bring it in to specification. The default gain is 86.5db, which equates to an AGC value of 692 (86.5 x 8).

e.g. if the reported signal level is –96dbm with the default AGC value, there is an error of 4. You would then increase the gain of the amplifier by (6 x 8 =48) the new AGC value would be 636 + 48 = 684.

Page: 82 M550/M551 Level 3 Service Manual

• This value would then be loaded into the AGC field of the radio configuration table in sate (remember to get from ms –change value –store in ms----- (if the board has not been calibrated the you will have to read from ram as it will only have the default values).

• Go back into the radio page and check if the reported level is within specification. If so retest the transceiver.

• If you cannot bring the receiver into specifications, follow the steps listed below.

This will check the functionality of all the main blocks of the receiver. (Antenna switch – IC500-, saw filters –IC 503 for GSM filter IC 502 for DCS filter-, RF chip set – IC600, IC601, IC 602- ) If any of these signals are missing then further investigation of that part of the circuit is required using the circuit diagrams. All the receiver signals and enables are identified on the following pages.

Page: 83 M550/M551 Level 3 Service Manual

N

RECEIVE DEBUG FLOW CHART

CHECK CHANNEL AND RECEIVE LEVEL INPUT. ENTER RECEIVE MODE.

Measure IC601 outputs

See section 1.12

Y

Measure IC600 inputs/outputs

See section 1.14

Trace missing signal

using section 1.14

Y

Suspect IC100

IC200

Measure IC500 outputs

See section 1.11

Measure X501 output

Y

Measure IC500 inputs

See section 1.11

Measure IC602 outputs

See section 1.13

Measure IC602 outputs

See section 1.13

Y

Measure IC601 inputs

See section 1.12

Page: 84 M550/M551 Level 3 Service Manual

RECEIVER PATH

Measurements taken at –65dBm

1.0.1. FRONT END IC (FEIC) IC500 RF

LOCATION NAME IN/OUT POWER LEVEL TO/FROM

L601 DCS_RX1, 2 OUTPUT -48dBm IC601 (19,20)

L600 GSM_RX1, 2 OUTPUT -48dBm IC601 (21,22)

ENABLES

LOCATION NAME ORIGINATOR GSM

RECEIVE

T500 (1) GSM_CTL T500 (1) 0V 0V

T500 (2) RF_TX_GSM_CTL IC100 (J10) 0V 0V

T500 (3) VCC_2V8_RF IC501 (5) 2.9Vdc 2.9Vdc

T500 (4) DCS_CTL T500 (4) 0V 0V

T500 (5) RF_TX_DCS_CTL IC100 (L13) 0V 0V

T500 (6) VCC_2V8_RF IC501 (5) 2.9Vdc 2.9Vdc

DCS RECEIVE

Page: 85 M550/M551 Level 3 Service Manual

1.0.2. TRANSCEIVER IC601

RF

LOCATION NAME IN/OUT POWER

LEVEL

IC601 (22) /C607

IC601 (21) /C611 IC601 (20) /C613 IC601 (19) /C614 IC601 (12) RF_LOP INPUT IC602 (23)

IC601 (13) RF_LON INPUT IC602 (24)

IC601 (3) CLKN INPUT -50dBm IC600 (10) 13Mhz

IC601 (4) CLKP INPUT -50dBm IC600 (9) 13Mhz

IC601 (1) ION OUTPUT IC600 (12) 100KHz

IC601 (2) IOP OUTPUT IC600 (11) 100KHz

EGSM_RX1 INPUT -48dBm IC502 (3) See freq table

EGSM_RX2 INPUT -48dBm IC502 (4) See freq table

DCS_RX1 INPUT -48dBm IC503 (3) See freq table

DCS_RX2 INPUT -48dBm IC503 (4) See freq table

TO/FROM FREQUENCY

ENABLES

LOCATION NAME ORIGINATOR GSM RECEIVE DCS RECEIVE

IC601 (31) RF_RADIO_ON IC100 (M12) 2.9V pulse 2.9V pulse

IC601 (32, 26,14)

VCC_2V8_RF IC501 (5)

(TP500)

2.9Vdc 2.9Vdc

Page: 86 M550/M551 Level 3 Service Manual

1.0.3. DUAL RF SYNTHESISER IC602

RF

LOCATION NAME IN/OUT POWER

LEVEL

IC602 (2) IFLB OUTPUT IC601 (12) ~Channel freq

IC602 (3) IFLA OUTPUT IC601 (13) ~Channel freq

IC602 (7) VCXO_13MHZ INPUT -50dBm IC603 (3)

ENABLES\ DATA

LOCATION NAME ORIGINATOR GSM

IC602(5,25,

28)

IC602 (9) RF_RADIO_ON IC100 (M12) 2.9V pulse at 217Hz

IC602 (11) RF_EN IC100 (H14) 3Vdc with -ve going data

IC602 (12) RF_TPU_CLK IC100 (J14) 3V +ve going data pulses

IC602 (13) RF_BB_TPU_DATA_IN IC100 (H11) 3V +ve going data pulses

VCC_2V8_RF IC501 (5) 2.9Vdc

TO/FROM FREQUENCY

DCS

RECEIVE

pulses

RECEIVE

Page: 87 M550/M551 Level 3 Service Manual

1.0.4. UNIVERSAL BASEBAND INTERFACE IC600

IF

LOCATION NAME IN/OUT POWER

LEVEL

IC600 (7) VCXO_13MHZ INPUT -50dBm IC603 (3)

IC600 (10) CLKN OUTPUT -50dBm IC601 (3)

IC600 (9) CLKP OUTPUT -50dBm IC601 (4)

IC600 (12) ION INPUT IC601 (1)

IC600 (11) IOP INPUT IC601 (2)

IC600 (19) RF_CLK13M OUTPUT +9dBm IC100 (E13)

ENABLES\ DATA

LOCATION NAME ORIGINATOR GSM/DCS RECEIVE

IC600 (2) RF_QP IC600 (2)

IC600 (3) RF_QN IC600 (3)

IC600 (4) RF_IP IC600 (4)

IC600 (5) RF_IN IC600 (5)

IC600 (6,13,28) VCC_2V8_RF IC501 (5) 2.9Vdc

TO/FROM FREQUENCY

C108

1.5V Pulses 217Hz with data on top

IC600 (14) RF_RADIO_ON IC100 (M12) 2.9V pulse at 217Hz

IC600 (16) RF_EN IC100 (H14) 3Vdc with -ve going

data pulses

IC600 (17) RF_TPU_CLK IC100 (J14) 3V +ve going data

pulses

IC600 (18) RF_BB_TPU_DATA_IN IC100 (H11) 3V +ve going data

pulses

Page: 88 M550/M551 Level 3 Service Manual

1.0.5. REFERENCE CLOCK IC603

LOCATION NAME IN/OUT LEVEL TO/FROM FREQUENCY

IC603 (4) VCC_2V8_RF INPUT 2.9Vdc IC501 (5) N/A

IC603 (3) VCXO_13MHZ OUTPUT -50dBm

IC603 (1) RF_AFC INPUT 1.24Vdc IC200 (J4) N/A

13MHz Checking

This section describes the checking procedure of the 13 MHz VCXO (IC603).

This VCXO must provide a 13 MHz reference clock within a precision of +/- 5 ppm, when the AFC is set to 1200 mV. To check the reference clock accuracy, we use the TX on GSM channel 62.

For further analysis, review the transmitter notes.

Page: 89 M550/M551 Level 3 Service Manual

2. TX POWER ADJUSTMENT

The phone transmitter is calibrated so that all power levels meet the GSM specifications. Calibration can be done on CH62, power levels 5, & 19 in the 900mhz band and CH698. PCL 0,15 in the 1800mhz band. This will prove the board is capable of calibration over the required range when placed back in the automatic test fixture.

PCl5 is the first point to be calibrated. A failure during calibration would indicate that the phone was not able to reach the target power. This could be a fault on the transceiver; a fixture connection problem or the test bay calibration offset factor being incorrect.

To check the transceiver is able to meet target power:

• Select the radio option in sate

• Power the transceiver at 3.8v

• Select 900 or 1800 band on middle channel.

• In the level field, enter a DAC of 900.

This should give you max power of > 31.7dBm for GSM or +29.6 dBm on DCS if the transceiver can reach this power on the bench then it should also do so when assembled.

• If the mobile cannot make max power or there is no TX power what so ever, debug the transmit path. (If, RF & TX VCO’s –IC602-, the pa IC700- antenna switch –IC500- and some important control signals). All the transmit signals and enables are identified on the following pages.

Page: 90 M550/M551 Level 3 Service Manual

N

N N N

N

TRANSMIT DEBUG FLOW CHART

CHECK CHANNEL, POWER STEP AND POWER STEP DAC VALUE. ENTER TRANSMIT MODE

Measure IC500 outputs

See section 2.15

Measure IC700 outputs

See section 2.14

Measure IC601 outputs

See section 2.11

Measure IC602 outputs

See section 2.12

Y

Measure IC500

Y

inputs

Measure IC700

Y

inputs

Measure IC601

Y

inputs

Measure MF501

See section 2.15

See section 2.14

See section 2.11

Measure IC603 outputs

See section 2.13

Measure IC602

Y

inputs

See section 2.12

Measure IC603 inputs

See section 2.15

Page: 91 M550/M551 Level 3 Service Manual

TRANSMIT PATH

Measurements taken at maximum power step

2.0.1. TRANSCEIVER IC601

RF

LOCATION NAME IN/OUT POWER

LEVEL

IC601 (12) RF_LOP INPUT -16dBm IC602 (23) See freq table

IC601 (13) RF_LON INPUT -16dBm IC602 (24) See freq table

IC601 (3) CLKN INPUT -50dBm IC600 (10) 13MHz

IC601 (4) CLKP INPUT -50dBm IC600 (9) 13MHz

IC601 (11) IF_LOP INPUT -33dBm IC602 (28) Freq Table

IC601 (10) IF_LON INPUT -33dBm IC602 (27) Freq Table

ENABLES

LOCATION NAME ORIGINATOR GSM

IC601 (31) RF_RADIO_ON IC100 (M12) 2.9V data pulses

IC601 (32, 26,14) IC601 (7) /C625 RF_QP IC200 (D8)

IC601 (8) /C625 RF_QN IC200 (D9)

VCC_2V8_RF IC501 (5) 2.9Vdc

TO/FROM FREQUENCY

DCS

TRANSMIT

1.5V Pulses 217Hz with data on top

TRANSMIT

IC601 (5) /C608 RF_IP IC200 (C9)

IC601 (6) /C608 RF_IN IC200 (C10)

Page: 92 M550/M551 Level 3 Service Manual

2.0.2. DUAL RF SYNTHESISER IC602

RF

LOCATION NAME IN/OUT POWER

LEVEL

IC602 (24) RFLOP OUTPUT -19dBm IC601 (12) See table

IC602 (23) RFLON OUTPUT -19dBm IC601 (13) See table

IC602 (7) VCXO_13MHZ INPUT -49dBm IC603 (3) 13MHz

IC602 (27) IFLOP OUTPUT -33dBm IC601 (9) Freq Table

IC602 (26) IFLON OUTPUT -33dBm IC601 (10) Freq Table

ENABLES\ DATA

LOCATION NAME ORIGINATOR GSM

IC602(5,25,

28)

IC602 (9) RF_RADIO_ON IC100 (M12) 2.9V pulse at 217Hz

IC602 (11) RF_EN IC100 (H14) 3Vdc with -ve going data pulses

VCC_2V8_RF IC501 (5) 2.9Vdc

TO/FROM FREQUENCY

DCS

TRANSMIT

IC602 (12) RF_TPU_CLK IC100 (J14) 3V +ve going data pulses

IC602 (13) RF_BB_TPU_DATA_IN IC100 (H11) 3V +ve going data pulses

2.0.3. REFERENCE CLOCK IC603

LOCATION NAME IN/OUT LEVEL TO/FROM FREQUENCY

IC603 (4) VCC_2V8_RF INPUT 2.9Vdc IC501 (5) N/A

IC603 (3) VCXO_13MHZ OUTPUT -49dBm 13MHz

IC603 (1) RF_AFC INPUT 1.24V IC200 (J4) N/A

Page: 93 M550/M551 Level 3 Service Manual

13MHz Checking

This section describes the checking procedure of the 13 MHz VCXO (IC603).

This VCXO must provide a 13 MHz reference clock within a precision of +/- 5 ppm, when the AFC is set to 1200 mV. To check the reference clock accuracy, we use the TX on GSM channel 62.

The procedure is the following:

A/ if it is not done, switch on the mobile, connect it to sate and go to radio menu.

B/ check AFC on C633. This point should be at 1.2 volt, if not to the base band debug section for omega. (IC200)

C/ connect the mobile to a GSM tester in egsm850 non-signalling mode.

D/ put the mobile in TX mode on GSM channel 62, perform a TX.

E/ if the absolute value of the frequency error is less than 4400 Hz (i.e. 5 ppm) and the mobile is transmitting the right power the VCXO is ok.

F/ if the absolute value of the frequency error is above 4400 Hz (i.e. 5 ppm), IC603 is out of specifications. Change the VCXO IC603, and restart this procedure to check this device once again.

G/ if the mobile is not transmitting, check the presence of the 13 MHz on C602, C617 and C630. Via these, the 13mhz is feeding the RF chip set (IC600 and IC602) and the base band. See points C1 and C2. If the 13MHhz signal is not present, check the soldering of these components.

AUTOMATIC FREQUENCY CONTROL (AFC) DAC CALIBRATION

To adjust the 13mhz reference frequency, a dc voltage variable between 0.5 VDC and 2.3 VDC is applied to the oscillator IC603. This voltage comes from the AFC to a converter in the iota IC and can be measured on tp204. Using sate negative values, (down to -4095) are sent to the DAC to give lower voltages. Positive values, (up to +4095), are sent to the DAC to give higher voltages. The aim of the calibration is to determine a DAC value that will give 1.00v out. This is done by measuring the voltage when first a low, then a high value is applied, interpolating the midpoints and extrapolating for 1v.

Components involved: iota, C633, R611, IC603, R205 and C225.

If the dc voltage doesn’t alter, try controlling another DAC, (power amplifier control APC_DAC for instance). If they both don’t work, suspect the iota or its communications with the calypso. Also check the iota reference voltage at C225. If only AFC fails, something may be pulling the output high or low. Measure resistance to ground, and to supply rails, and check discrete components involved.

Page: 94 M550/M551 Level 3 Service Manual

2.0.4. POWER AMPLIFIER IC700

RF

LOCATION NAME IN/OUT POWER

LEVEL

R701 TX_VCO_DCS INPUT -4dBm IC601 (24) See freq table

R704 TX_VCO_GSM INPUT -6dBm IC601 (25) See freq table

L700 PCS_PA_TX OUTPUT 26dBm IC500 (11) See freq table

R706 GSM_PA_TX OUTPUT 29dBm IC500 (1) See freq table

ENABLES

LOCATION NAME ORIGINATOR GSM

C701 RF_nGSM_DCS IC100 (M14) V 2.9V pulse

C703 RF_PA_CTL_EN IC100 (L12) 2.9V pulse 2.9V pulse

C717 VBAT X400 (3) VBATT VBATT

C712 VCC_2V8_RF IC501 (5) 2.9Vdc 2.9Vdc

R702 RF_RAMP_DAC IC200 (K4) 217Hz pulse size dependant on

TO/FROM FREQUENCY

DCS

TRANSMIT

TX level

TRANSMIT

Page: 95 M550/M551 Level 3 Service Manual

2.0.5. FRONT END IC (FEIC) IC500 RF

LOCATION NAME IN/OUT POWER

LEVEL

X501 ANTENNA OUTPUT GSM 31dBm

DCS 27dBm

L701 DCS_PA_TX INPUT 26dBm IC502 (1)

C722 GSM_PA_TX INPUT 31dBm IC503 (1)

ENABLES

LOCATION NAME ORIGINATOR GSM

TRANSMIT

T500 (1) GSM_CTL T500 (1) 2.9V pulse 0V

T500 (2) RF_TX_GSM_CTL IC100 (J10) 2.9V pulse 0V

T500 (3) VCC_2V8_RF IC501 (5) 2.9Vdc 2.9Vdc

T500 (4) DCS_CTL T500 (4) 0V 2.9V pulse

T500 (5) RF_TX_DCS_CTL IC100 (L13) 0V 2.9V pulse

T500 (6) VCC_2V8_RF IC501 (5) 2.9Vdc 2.9Vdc

TO/FROM

ANTENNA

DCS TRANSMIT

3. FREQUENCY TABLES

EGSM DCS GSM850 PCS IF Freq

RF VCO

Ch 25-49 790 Mhz Other 798 MHz =FTX+IF/2 =FTX-IF/2 =FTX+IF/2 =FTX-IF/2

766Mhz 896Mhz 854Mhz

Page: 96 M550/M551 Level 3 Service Manual

Channel

Radio

Band

GSM850

EGSM

DCS1800

PCS1900

810 1909.8 1989.8 854.0 1482.8 1989.7

Number

(ARFCN) Tx Frq Rx Frq IF PLL RF PLL (Tx) RF PLL (Rx)

128 824.2 869.2 896.0 1272.2 1738.2 189 836.4 881.4 896.0 1284.4 1762.6 251 848.8 893.8 896.0 1296.8 1787.4

975 880.2 925.2 798.0 1279.2 1850.2

1023 889.8 934.8 798.0 1288.2 1869.4

1 890.2 935.2 798.0 1289.2 1870.2 26 895.2 940.2 790.0 1290.0 1880.2 49 899.8 944.8 790.0 1295.0 1889.4 50 900.0 945.0 798.0 1889.8 62 902.4 947.4 798.0 1301.4 1894.6

124 914.8 959.8 798.0 1314.0 1919.4

512 1710.2 1805.2 766.0 1327.2 1805.1 700 1747.8 1842.4 766.0 1364.4 1842.3 885 1784.8 1879.8 766.0 1401.8 1879.7

512 1850.2 1930.2 854.0 1423.2 1930.1 661 1880.0 1960.0 854.0 1453.0 1959.9

4. CALL TESTS

To verify and check any of the call tests, a call will have to be established with a GSM tester – CMD, CMU etc. Ensure that the test jig has a test SIM card. When you establish a call, you have to check the main GSM parameters.

BER

BER is measured as a % of the number of bits checked. The specification for type ii bits, which have no error correction is 0-2.4% @ -102dbm. For type 1b bits, which have error correction no errors are allowed. If the BER is in specification it indicates that the synthesizers are tuned correctly, the VGA in the receiver is tracking the input power and providing the correct signal amplitude to the demodulator. It also shows that the equalizer in the processor is ok.

• If the BER is completely out (50%) then check that the main blocks of the transceiver are functioning correctly (VCO’s, LNA). The main blocks should be functional if all previous tests passed.

• If the BER is just out of specification the problem is most likely in the RX front end, i.e., The LNA. Check the level of signal loss through the antenna switch, saw filter and input to the LNA. Section 2 lists all the steps necessary to do this. If the loss through any of these devices is significantly more than listed in section 2 try re-soldering the device. If the BER is still out of specification then check that the discrete components in the receive path are the correct value.

RX LEVEL & QUALITY

Rx level is a report of the signal level the mobile is receiving; if the receiver is calibrated correctly, the mobile should report the correct level. Rx quality will indicate errors in the received data, if the rx level is greater than four then the BER will also be high.

Try calibrating the PCB again, if this is not successful then check all the components listed above for BER as well as the IF saw filter and its matching components.

Page: 97

M550/M551 Level 3 Service Manual

POWER vs. TIME MASK

The time mask test indicates sure that the transmit burst switching is controlled correctly. A time mask pass indicates the ramp control circuitry and power amp switching are ok. The component that makes up this circuitry is IC700 - (pa + pa controller). Check these components and the following control signals: RF_ PA_CTL_EN, RF_NGSM_DCS, AND RF_RAMP_DAC.

PEAK & RMS PHASE ERROR

Phase and frequency measurements check that the channel synthesizer has changed

frequency and settled fast enough. Good peak & RMS phase error highlights the performance

of the pre-modulation Gaussian filtering and that the i/q modulator has been calibrated

correctly. It can also show up performance issues with the pa –IC 700- and the inter section

screening. Check: the pa (IC700) and associated components, the RF & if VCO (IC602) and

associated components.

Page:98

M550/M551 Level 3 Service Manual

Section 7

Software Download

Page:99

M550/M551 Level 3 Service Manual

Sendo Software Installation

Dongle Installation Procedure

WHENEVER A DONGLE IS INSTALLED THE FOLLOWING “SERVICE CENTER DONGLE CONTENT FORM” MUST BE COMPLETED AND SENT TO SENDO CUSTOMER SERVICE.

This form is used to both register the dongle number and details the security steps that must be taken by the service center to protect the dongle from loss or misuse.

IMPORTANT NOTE (minimum 800Mhz processor) with Windows 2000

The software installation can only be used on PC’s

or XP.

Page100

M550/M551 Level 3 Service Manual

Service Center Dongle Content form

I ________________________________, Acknowledge receipt of the Dongle Set out below.

I understand that the Dongle is a key piece of Sendo Ltd UK equipment and that extra special care must be taken to avoid its loss and misuse.

I confirm:

1) That the Pc with the Downloading software will be switched off at night and when unattended it will be locked.

2) The Dongle will; not be left attached to the pc and or unattended at any time. It will be kept in a safe place, out of the office, out of business hours. It will be kept by a authorized person at all times.

3) I will report any loss, damage, or theft whether malicious or accidental immediately without fail.

4) I will not give to a 3

I understand that I am liable for any misuse of this Dongle and its associated Software and I will ensure that no misuse or abuse takes place.

Sendo reserve the right to remove the Dongle and software at any time with out notice.

Signed………………………………. Date……………………………………..

Dongle Colour: Dongle Serial No:

DDoonnggllee TTyyppee::

PPrrootteecctteedd SSooffttwwaarree::

SSppeecciiaall NNootteess

3rd party NDA checked:

rd

party whatsoever and it will be returned upon request.

Dongle Returned to:

Of ___________________________________

1

(signed) Date

MMaasstteerr SSeerriiaall NNuummbbeerr::

DDoonnggllee LLooccaattiioonn::

Rev1.0 Date 09/04/2001 Customer Service

Sendo M550 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual