Nokia 7270, 6170 Service Manual 06 rm 8 troubleshooting

Nokia Customer Care

RM-8/RM-47/RM-48 Series Transceivers

6 - Troubleshooting Instructions

RM-8/RM-47/RM-48 Company confidential

6 - Troubleshooting Instructions Nokia Customer Care

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RM-8/RM-47/RM-48

Nokia Customer Care

Table of Contents

Page No

Introduction ........................................................................................................ 1

General Failures ................................................................................................. 2

Phone is dead .................................................................................................... 2

Flash programming doesn’t work ....................................................................... 3

Charging Failure ................................................................................................ 6

Phone doesn’t stay on, or phone is jammed ...................................................... 7

Display Information: “Contact Service” .............................................................. 8

Function Failures ............................................................................................. 10

Camera Failure ................................................................................................ 10

Camera viewfinder failure ................................................................................ 11

FM-radio Failure ............................................................................................... 12

Infrared Communication Failure ....................................................................... 13

SIM Failure ....................................................................................................... 14

Display Failure ................................................................................................. 15

Main display failure ........................................................................................ 16

Mini display failure ......................................................................................... 17

Main display illumination fault ........................................................................ 18

Mini display illumination fault ......................................................................... 19

USB Data Transmission Failure ....................................................................... 20

Audio Failure .................................................................................................... 21

Uplink or downlink failure ............................................................................... 21

Uplink missing audio signal............................................................................ 22

Uplink weak audio signal ............................................................................... 23

Uplink distorted audio signal .......................................................................... 24

Uplink TDMA noise ........................................................................................ 25

Downlink missing audio signal ....................................................................... 26

Downlink weak audio signal........................................................................... 27

Downlink distorted audio signal ..................................................................... 28

Downlink noise in audio signal....................................................................... 29

Downlink TDMA noise.................................................................................... 30

Various noise problems ................................................................................. 31

Vibra errors .................................................................................................... 32

BackLight Failure ............................................................................................. 33

Key Failure ....................................................................................................... 34

Power Key Failure.......................................................................................... 34

Volume key failure ......................................................................................... 35

Keypad failure ................................................................................................ 36

RF Troubleshooting ......................................................................................... 37

RF Key Component Placement....................................................................... 38

ISSUE 2 03/2005 COMPANY CONFIDENTIAL 3

RM-8/RM-47/RM-48

Nokia Customer Care

RF test points ................................................................................................... 39

Receiver ........................................................................................................... 40

Transmitter ....................................................................................................... 41

Synthesizer ...................................................................................................... 42

RF in General.................................................................................................... 43

RF Power Supply Configuration ..................................................................... 45

General Specifications of Transceiver........................................................... 46

Receiver Verification and Troubleshooting................................................... 48

General instructions for RX Troubleshooting ................................................... 48

Measuring RX I/Q Signals using RSSI Reading ............................................ 48

Measuring RX Performance using SNR Measurement ................................. 49

Measuring Front-End Power Levels using Spectrum Analyzer...................... 51

Measuring Analogue RX I/Q Signals using Oscilloscope .............................. 51

Fault Finding Chart of the Receiver ................................................................. 51

RX Signal Paths ............................................................................................... 56

Antenna Switch (RX/TX Switch) .................................................................... 56

RX front-end................................................................................................... 57

RX paths of RF ASIC ..................................................................................... 57

Transmitter ....................................................................................................... 58

General Instructions for Transmitter Troubleshooting ...................................... 58

Transmitter troubleshooting ............................................................................. 58

Antenna Switch (TX/RX switch) ..................................................................... 58

GSM850 Transmitter ........................................................................................ 59

General Instructions for GSM850 TX Troubleshooting .................................. 59

Fault Finding Chart for GSM850 Transmitter................................................. 62

GSM900 Transmitter ........................................................................................ 63

General Instructions for GSM TX Troubleshooting ........................................ 63

Fault Finding Chart for GSM900 Transmitter................................................. 65

GSM1800 Transmitter ...................................................................................... 68

General instructions for GSM1800 TX Troubleshooting ................................ 68

Fault finding chart for GSM1800 transmitter .................................................. 70

GSM1900 Transmitter ...................................................................................... 71

General instructions for GSM1900 TX Troubleshooting ................................ 71

Fault finding chart for GSM1900 transmitter .................................................. 73

Synthesizer ....................................................................................................... 77

Synthesizer operation check ............................................................................ 77

Reference Oscillator 26 MHz (VCTCXO) ......................................................... 79

Voltage Controlled Oscillator (VCO) ................................................................ 79

Frequencies ..................................................................................................... 81

DC Supply Current Check ............................................................................... 83

4 COMPANY CONFIDENTIAL ISSUE 2 03/2005

RM-8/RM-47/RM-48

Nokia Customer Care

Phoenix Tuning ................................................................................................ 84

General instructions for tuning: ...................................................................... 84

RF Tuning after Repairs ................................................................................... 84

Semi-automatic Calibrations & Measurements - step by step: RX/TX and GSM-Bands

84

RX Calibration................................................................................................ 84

RX Band Filter Response Compensation ...................................................... 88

RX Channel Select Filter Calibration ............................................................. 92

TX Power Level Tuning.................................................................................. 94

TX I/Q Tuning................................................................................................. 98

Fully automatic Calibration, Tuning & Measurement by Phoenix “Auto-Tune” 104

Preparations for Phoenix ............................................................................. 104

Automatic tuning procedure ......................................................................... 107

FM-radio troubleshooting (RM-8 only) ......................................................... 109

FM-Radio Troubleshooting ............................................................................ 110

ISSUE 2 03/2005 COMPANY CONFIDENTIAL 5

RM-8/RM-47/RM-48

Nokia Customer Care

Introduction

This document describes in overview the different hardware error possibilities for the RM-8, RM-47 and RM-48 phone.

Not every possible hardware error is described in this document, but only those possible to correct.

Issue 2 03/2005 COMPANY CONFIDENTIAL 6

Issue 2 03/2005

Nokia Customer Care

General Failures

■ Phone is dead

This means that the phone doesn’t use any current at all when supply is connected and/or power key is pressed. It is assumed that the voltage supplied is 3,9Vdc. UEMEK will prevent any functionality at battery/supply levels below 2,9Vdc and the software will shut the phone down at 3,1Vdc.

7 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Phone is dead

Nokia Customer Care

Figure 1: Phone is dead

Yes

Measure voltage on L2350, L2351,

L2352, L2353, L2354, L2355 and

L2200. Should be ~3,9V

Yes

Measure voltages on both sides of

R2407 when power key is pressed.

Should be ~0V

Yes

Sleep clock on J2800:

~32,768 kHz, 1,8Vpp

Yes

Measure voltage on PURX = 1,8Vdc

on J2802. ~1 sec after power key

is pressed.

Yes

Measure voltage on VR3=2,78 Vdc

onC2207 pin 1

No

Failure in VBATT line:

Check X2000, L2350, L2351, L2352,

L2353, L2354, L2355, L2200, C2350,

C2351, C2352 and PWB

Check:

R2407, S2401 and PWB

Check:

B2200, C2202, C2203, D2200

and PWB

Check:

D2200 and PWB

Check:

D2200, C2207 and PWB

Yes

Verify that system clock is @

~26 MHz, min 300m VACpp on C2901 pin 2 towards D2800 (TIKU) with regular probe C in ~10-13pF /

10M

Yes

Check:

D2800 (TIKU) and D3000 (flash)

and D3001 (SDRAM)

No

C2901, R2901, N7500 (Helgo),

Check:

G7501 (26 MHz XTAL) and PWB

■ Flash programming doesn’t work

The flash programming on RM-8 boards is only possible via the pads on the PWB.

In case of Flash failure in production (FLALI station), problem is most likely related to SMD problems. Possible failures could be short-circuiting of balls under µBGAs (e.g. UEMEK, TIKUEDGE, SDRAM, FLASH), missing or misaligned components.

Issue 2 03/2005 COMPANY CONFIDENTIAL 8

Issue 2 03/2005

Nokia Customer Care

In flash programming error cases the flash prommer (via Phoenix or Darium) can give some information about the fault. The fault information messages could be:

• Phone doesn't set Flashbus TXD line high after VCC is switch on.

• External RAM test failed.

These errors are some of the most common errors and based on this, a fault finding diagram for flash programming is shown below. Various errors can appear from the prommer when flashing the phone - not all of them can be directly linked to the HW or phone.

Because of the use of uBGA components, it is not possible to verify on the diagram, if there is a short circuit in control and address/data lines on TIKUEDGE, NOR flash or SDRAM.

Figure 2: Flash programming doesn’t work

Flash programming does not work

Re-solder/Replace

component

Fix the connections

if possible. Else

scrap the phone

Prommer information is:

External RAM test failed.

(C108)

No

Check SDRAM orientation and

placement. OK?

Yes

No

Check PWB (if possible) and

power lines. Connections OK?

Yes

Replace the SDRAM Flash again

Prommer information is: Phone does not set Flashbus TXD line high after VCC is switched on.

Check J3401, R3400, R3403,

R3405. Connections OK?

Yes

Try reading MCU ID with

Phoenix. Reading OK?

Yes

Try reading flash ID with

Phoenix. Reading OK?

No

Re-solder/Replace

component

Replace UEMEK

or TIKU

Replace NOR

flash

9 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Nokia Customer Care

Table 1: Most common error messages

Error Description Used signals/components Points to Check

VBAT at C2228

VCORE at C2222,

VIO at C3003

VFLASH1 at R2204

FBUSRX at R3403

FBUSTX state at J2812(TIKU)-

>R3400(UEMEK)

SLEEPX at J2801

VR3 at C2227 and C7526

RFCLOCK at G7501 and R2901

MBUS pulse train at R3405

FBUSTX state at J2812(TIKU)-

>R3400(UEMEK)

MBUS pulse train at R3405

FBUSRX serial data at R3403

FBUSTX state at J2812(TIKU)-

>R3400(UEMEK)

Prommer SW

C101

C102

C103

C107

A204

A387

C583 C683

C584 C684

C585 C685

C586 C686

The Phone does not

set Flashbus TXD

line high after the

The Phone does not

set Flashbus TXD

line low after the line

has been high. The

Prommer generates

this error also when

the Phone is not connected to the

The Phone MCU

has not received the

first dummy word correctly from the Prommer after the

The Phone MCU

can not start

Secondary code

manufacturer and

device IDs in the existing Algorithm files do not match

with the IDs

received from the

target phone.

The MCU ID in the

FIASCO_MCU_ID_I

NFO block of the

MCUSW file does

not match with the

ID received from the

target phone.

The Prommer has

not received Phone acknowledge to the

The Phone has generated NAK

signal during data

block transfer. The Phone has not acknowledged data

block correctly.

The erasing status

response from the

Phone informs about

startup.

Prommer.

startup.

correctly. The flash

message.

fail.

VBAT, VCORE, VIO, VFLASH1

BSI and FBUSRX from Prommer to UEMEK

FBUSTX from TIKU->UEMEK->Prommer (stuck at ‘0’)

SLEEPX from UEMEK to TIKU

RFCLOCK (VCTCX->Helgo->TIKU)

MBUS From Prommer->UEMEK->TIKU(stuck at ‘1’)

FBUSTX from TIKU->UEMEK->Prommer(stuck at ‘1’)

MBUS from Prommer->UEMEK->TIKU(stuck at ‘0’)

FBUSRX from Promm er->UEMEK->TIKU

FBUSTX from TIKU->UEMEK->Prommer

Signals between TIKU and Flash

PURX, VR3

TIKU

Flash

TIKU Prommer SW

Flash and TIKU

Flash

BSI pulse at C2003 when flashing starts

PURX state transition ‘0’ to ‘1’ at J2802

Issue 2 03/2005 COMPANY CONFIDENTIAL 10

Nokia Customer Care

■ Charging Failure

Charging fails and no current

drawn from ‘charger’

Yes

Issue 2 03/2005

Measure Vchar voltage on V2000. Is it > 3.0V?

Yes

Recalibrate charger circuitry

and retest. Did it work?

Yes

END

Display information when charger

connected: “Not charging”

Yes

Recalibrate charger circuitry

and retest. Did it work?

No

Yes

X2003, F2000, L2000, V2000,

Check:

C2005, C2006 and PWB

D2200 (UEMEK) is faulty

END

No

Verify through Phoenix that BSI=

~68k Ohm (BL-4C) and BTEMP=

~47k Ohm @ roomtemperature

(~25 C)

Yes

Measure voltage on R2200 towards

D2200. Should be the same as

Vbat voltage

Yes

Phone should work. If not,

change whole engine board

No

BSI: Battery (BL-4C), R2015

C2003, R2361, R2362 and PWB

BTEMP: R2000, C2004, R2360,

R2200, D2200 (UEMEK) and PWB

Check:

R2363 and PWB

Check:

11 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Nokia Customer Care

■ Phone doesn’t stay on, or phone is jammed

If this kind of a failure is presenting itself immediately after FLALI, it is most likely caused by ASICs missing contact with PWB.

If the MCU doesn’t service the watchdog register within the UEMEK, the operations watchdog will run out after approximately 32 seconds. It is not possible to measure this service routine.

Figure 3: Phone doesn’t stay on, or is jammed

Phone doesn’t stay on or phone is

jammed

Yes

Sleep clock on J2800 ~32,768 kHz; 1,8Vpp

Yes

Verify that system clock is @

~26 MHz, min 300m VACpp on C2901 pin2 towards D2800 (TIKU) with regular probe Cin ~10-13pF /

10M

Yes

Measure voltage on PURX=

1,8 Vdc on J2802

~1 sec after power key is pressed

Yes

No

B2200, D2200 (UEMEK),

Check:

C2202, C2203 and PWB

Check:

C2901, R2901, N7500 (Helgo),

G7501 (26 MHz XTAL) and PWB

Check:

D2200 (UEMEK) and PWB

UI functionality and keys react to

pressure?

Yes

Is everything working until phone

shuts down after ~32 sec?

No

Retest and if phone still doesn’t work,

change whole engine board

No

D2800, D3000, D3001, Z2400, Z2401,

keymat, lightguide and PWB

Yes

Change D2200 (UEMEK)

Check:

Issue 2 03/2005 COMPANY CONFIDENTIAL 12

Issue 2 03/2005

Nokia Customer Care

■ Display Information: “Contact Service”

When this error appears in the display it means that one or more of the internal baseband tests has failed. The baseband tests (self tests) are performed each time the phone is powered on. The self tests are divided into those performed while powering up (Start up tests) and the ones that can be executed with a PC using Phoenix (Runtime tests). The following Start-up tests are performed during power up:

AUX DA LOOP TEST

EAR DATA LOOP TEST

KEYBOARD STUCK TEST

MBUS RX TX LOOP TEST

PPM VALIDITY TEST

SIM CLK LOOP TEST

SIM IO CTRL LOOP TEST

SLEEP X LOOP TEST

TX IDP LOOP TEST

TX IQ DP LOOP TEST

BACKUP BATT TEST

CAMERA IF TEST

SIM LOCK TEST

WARRANTY TEST

FLASH CHECKSUM TEST

RADIO TEST

IR IF_TEST

UEM CBUS IF TEST

PA TEMP TEST

EXT RAM DATA BUS TEST

EXT RAM ADDR BUS TEST

If all these self tests are passed, the phone will start up.

From Phoenix it’s possible to run all the self tests and the additional “Runtime test”. The test cases can be seen below.

13 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Nokia Customer Care

Figure 4:Display Information: “Contact Service”

Issue 2 03/2005 COMPANY CONFIDENTIAL 14

Nokia Customer Care

Function Failures

■ Camera Failure

Start

Issue 2 03/2005

Does the

viewfinder

start?

Yes

End

No

Check engine PWB

in module jig. Does

camera work?

No

Check X2400.

Failure in

Lower block

OK?

Yes

Displays (VCORE_LIN) working OK?

Yes

No

Change/fix and retest

No

Failure in

Upper block OR

Hinge Flex

Check

VCORE_LIN 1.8V

from module jig.

OK?

Check Upper block

in module jig. Does

camera work?

No

Failure in

Upper block

Check Camera positioning in socket X3603.

Yes

Check X3602,

C3609-C3612,

Z3601, C3624- C3625 and lines. OK?

Yes

Failure in

Camera module

No

Check C2222

(1/2). OK?

Yes

OK?

YesYes

No

Failure in Hinge

Flex. Change

and retest.

Adjust & retest

According to repair instructions –repair

or change Upper

block Flex As sy

Change Upper

block Flex Assy

and retest.

Change/fix

defect component

and retest

Measure

CamCtrlClk from

module jigs

test point. Is it

13 MHz?

No

Change

TIKU

(D2800)

Retest

Change UEMEK

(D2200)

15 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

■ Camera viewfinder failure

Viewfinder working but no

picture taken when pressing

select-key

Nokia Customer Care

Select key

functional ?

Yes

R3304 = 6,5 MHz

clock when

pressing select?

Yes

No

Check

keyboard with

Phoenix

Check for

short circuit

of R3304

Z2401 and

domesheet

OK ?

Yes

Short circuit?

Yes

No

Replace

Z2401 and/or

domesheet

PWB

failure

Camera

failure

Replace

component

Reflash phone

Issue 2 03/2005 COMPANY CONFIDENTIAL 16

Nokia Customer Care

■ FM-radio Failure

The FM-radio troubleshooting guide is in the RF section.

Issue 2 03/2005

17 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

■ Infrared Communication Failure

IrDA failure

Yes

Nokia Customer Care

Measure

VBAT at C2600

= 3,7- 4,2 V?

Yes

Measure

VFLASH1 at

C2602

= 2,78 V?

Yes

Measure

VIO at

C2603

= 1,80 V?

No

Defect PWB

Replace

D2200

Replace

D2200

Yes

Measure

activity TXD

on N2600

pin3?

Yes

Replace

N2600

No

Replace

D2800

Issue 2 03/2005 COMPANY CONFIDENTIAL 18

Issue 2 03/2005

Nokia Customer Care

■ SIM Failure

The hardware of the SIM interface from the UEMEK (D2200) to the SIM connector (X2700) can be tested without a SIM card. When the power is switched on, the phone first checks for a 1,8V SIM card and then a 3V SIM card. The phone will try this four times, whereafter it will display "Insert SIM card".

The error ”SIM card rejected” means that the ATR message received from the SIM card is corrupted, e.g. data signal levels are wrong. The first data is always ATR and it is sent from card to phone.

Figure 5: SIM Failure

19 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

■ Display Failure

Start

Nokia Customer Care

Do

both displays

start ?

Yes

No

Both

displays

fail?

Yes

Check Hinge

flex, X2400,

X3602. OK ?

Yes

Measure VFlash1

Measure

at 1/2 of C2220

VDD (~2,8V)

and Vcore_Lin at

from C2220

1/2 of C2222.

VDDI (~1,8V)

OK?

from C2222

No

Main display

fails

Mini display

fails

Change defect

components.

OK ?

Check Hinge

flex, X2400,

X3602 and

lines. OK ?

No

Go to “Main display

failure”

Go to “Mini display

failure”

Change upper

block.

Change UEMEK

(D2200)

Yes

END

Measure RESX

Measure

from X2400

RESX from

(~1,8V). OK?

C2222

(~1,8V). OK ?

Yes

Are the

backlights OK ?

No

Check Hinge

flex, X2400,

X3602 and

lines. OK ?

No

Change TIKU

(D2800)

Go to

“Main/Mini display

illumination

fault”

Issue 2 03/2005 COMPANY CONFIDENTIAL 20

Nokia Customer Care

Main display failure

Start

Issue 2 03/2005

Main display

fails ?

No

Yes

Check hinge flex,

X2400, X3600

and X3602. OK ?

Yes

Measure

VFlash1

VDD (~2,8V)

from C3607,

Vcore_lin (1,8V)

VDDI (~1,8V)

from C3608.

OK ?

No

Change defect

components.

OK ?

Change UEMEK

(D2200)

Yes

END

21 COMPANY CONFIDENTIAL Issue 2 03/2005

Change display

module

RM-8/RM-47/RM-48

Mini display failure

Start

Nokia Customer Care

Mini display

fails ?

No

Yes

Check hinge flex,

X2400, X3601

and X3602. OK ?

Yes

Measure

VFlash1 (

VDD (~2,8V) from C3606,

Vcore_lin (1,8V)

VDDI (~1,8V)

from C3605.

OK ?

Yes

No

Change defect

components.

OK ?

Change UEMEK

(D2200)

END

Issue 2 03/2005 COMPANY CONFIDENTIAL 22

Change display

module

Nokia Customer Care

Main display illumination fault

Start

Issue 2 03/2005

Are the Main

display

backlights

OK ?

Yes

No

Check N2400, V2404,

R2403, C2411- C2413,

L2400, X2400, X3602

(Hinge flex) and

X3600. OK ?

Yes

Measure

VLED+ (~14V)

from V2404.

OK ?

No

Change defect

components.

Retest.

Change UEMEK

(D2200)

Yes

END

23 COMPANY CONFIDENTIAL Issue 2 03/2005

Change display

module

RM-8/RM-47/RM-48

Mini display illumination fault

Start

Nokia Customer Care

Are the Mini

display

backlights

OK ?

Yes

No

Check D2400, R2400,

C2402, C2403, X2400, X3602

(Hinge flex) and

X3601. OK ?

Yes

Check LED’s

V3600, V3601,

V3602 and

lines.

OK ?

No

Change defect

components.

Retest.

Change defect

components.

Retest.

Yes

Change UEMEK

(D2200).

END

Issue 2 03/2005 COMPANY CONFIDENTIAL 24

Nokia Customer Care

■ USB Data Transmission Failure

Issue 2 03/2005

25 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

■ Audio Failure

Uplink or downlink failure

Nokia Customer Care

Start

Uplink = outgoing audio from e.g. microphone

Is there

an audio

signal?

Yes

Is audio

level

sufficient?

Yes

Is audio

signal

undistorted?

Yes

Is TDMA

noise

inaudible?

No

Uplink

Go to “Uplink

missing audio

signal”

Go to “Uplink

weak audio

signal

Go to “Uplink

distorted audio

signal”

Go to “Uplink TDMA noise”

”

Is problem

uplink or

downlink?

Downlink = incoming audio to e.g. earpiece

Downlink

Is there

an audio

signal?

Yes

Is audio

level

sufficient?

Yes

Is audio

signal

undistorted?

Yes

Is audio

signal free

of noise?

No

Go to

“Downlink

missing audio

signal”

Go to

“Downlink

weak audio

signal

”

Go to

“Downlink

distorted audio

signal”

Go to

“Downlink

audio signal

noise”

Yes

Is there no

acoustical

feedback?

Yes

No

Go to

“Acoustical

feedback”

Is TDMA

noise

inaudible?

Yes

Is there no acoustical feedback?

Yes

Click noise, audio signal too loud or

bad picture/

sound

synchronization

No

Go to

“Downlink

TDMA noise ”

Go to

“Acoustical

feedback”

Software

error or bad

TIKU

Issue 2 03/2005 COMPANY CONFIDENTIAL 26

Nokia Customer Care

Uplink missing audio signal

Issue 2 03/2005

Start

Yes

Is mute

deactivated?

Yes

Is problem

present both with

hand portable

and accessory?

No

Is problem

solved when

using

accessory?

Yes

Measure

mic bias. Is it

~2.1V?

No

Deactivate mute

Yes

No

Accessory is

C2107, C2108 and R2104,

in menu

defective

Are any of

the bias components

defective? (Check R2113,

for hand portable and

R2105, C2111, C2112

and R2107 for

accessory)

Yes

NoNo

Replace

UEMEK

Are microphone

contacts and PWB

pads OK?

Yes

Are any of

the components

(L2100, C2109, R2100,

C2100 or C2101 for hand

portable and L2101, C2104

or C2103 for accessory)

missing or

damaged?

No

Replace

microphone

Yes

No

Replace

defective parts.

Is bias ~2.1V?

Yes

No

Clean contacts and pads. If

tracks are badly corroded it

may not be possible to

repair the phone

Replace

defective parts

27 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Uplink weak audio signal

Start

Nokia Customer Care

Is

microphone

opening

clean?

Yes

Measure bias. Is it

~2.1V?

Yes

No

Clean opening

Are any of the bias components defective? (Check R2113, C2107,

C2108 and R2104)

Yes

Replace

defective parts.

Is bias ~2.1V?

Yes

No

Replace

UEMEK

Are microphone

contacts and PWB

pads OK?

Yes

Are any of the

components

L2100, C2109,

R2100, C2101 or C2100

missing or damaged?

No

Replace

microphone

No

Yes

Clean contacts and pads. If

tracks are badly corroded it

may not be possible to

repair the phone

Replace

defective parts

Issue 2 03/2005 COMPANY CONFIDENTIAL 28

Nokia Customer Care

Uplink distorted audio signal

Start

Issue 2 03/2005

Is there

distortion when

using

accessory?

No

Measure bias. Is it

~2.1V?

Yes

No

Yes

Defect accessory

Are any of the bias

components defective?

(Check R2113, C2107,

C2108 and R2104)

Yes

Replace

defective parts.

Is bias ~2.1V?

No

Replace

UEMEK

Are microphone

contacts and PWB

pads OK?

Yes

Are any of the

components

L2100,C2109, R2100,

C2100 or C2101

missing or

damaged?

No

Replace

microphone

No

Clean contacts and pads. If

tracks are badly corroded it

may not be possible to

repair the phone

Yes

Replace

defective parts

29 COMPANY CONFIDENTIAL Issue 2 03/2005

RM-8/RM-47/RM-48

Uplink TDMA noise

Nokia Customer Care

Start

Is there TDMA

noise both in hand

portable and when

using accessory?

Yes

Replace

the microphone.

Is there still

noise?

Yes

Check for loose,

missing or damaged shielding cans. Check C2101, C2107 - C2109 for handportable and

C2110 - C2112 for

accessory

No

Is there noise

only in hand

portable mode?

Yes

Defective

microphone

No

Defective accessory

Issue 2 03/2005 COMPANY CONFIDENTIAL 30