Nokia Ringo Disassembly Instructions

PAMS Technical Documentation

NHX–4N

DISASSEMBLY &

TROUBLESHOOTING

INSTRUCTIONS

Original 01/98

Copyright  1998 Nokia Mobile Phones. All rights reserved.

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Amendment
Number

Technical Documentation

AMENDMENT RECORD SHEET

Date Inserted By Comments

Page 2

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

CONTENTS

Disassembly instructions Page 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Trobleshooting Page 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Troubleshooting Page 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Logic fault Page 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receiver fault Page 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmitter fault Page 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Audio fault Page 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Display or keyboard fault Page 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Call set–up fault Page 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NHX–4N

Page No

Original, 01/98

Page 3

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Disassembly instructions

1) Remove the
antenna

2) Remove screw
covers (3 pcs) with
screwdriver

Technical Documentation

5) Disconnect:
battery connector (1),
microphone connector (2),
and earphone connector (3)
with tweezers

3) Remove back
cover screws (3 pcs)

4) Remove
back cover

6) Remove
battery

7) Remove
chassis screws

Page 4

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

8) Remove
transceiver
module

NHX–4N

10) Lift display carefullly
Remove screws (3 pcs)

9) Turn around,
Loosen the light guide carefully
from both sides of the PCB with
flat headed tool

11) Chassis and module
can now be separated

Original, 01/98

Page 5

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

General Trobleshooting

The object of troubleshooting is to define the faulty module block, and then to
locate the faulty component. The troubleshooting diagram has been planned so
that the fault, whatever it is, can be found as simply as possible.

The flow charts give you the overview of the blocks. The purpose is that you
proceed through the flow diagram so that, if your answer is YES for the asked
question, go straight to the next level, but if your answer is NO, go the sub­branch.

Required servicing equipment:
– PC for Service Software
– Power supply (2.0A)
– Digital multimeter
– Oscilloscope
– Signal generator
– Spectrum analyzer

Technical Documentation

– RF cables
– Service cable SCN–3
– RF–adapter AAT–4X
– Test jig JBS–3N
– RS232/MBUS adapter

Page 6

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

General Troubleshooting

START

Will turn into

local mode ?

OK

Receiver OK ?
(SINAD OK)

The General troubleshooting chart shows
the most common fault areas These seven
fault types can be used to define the pos­sible fault.

Logic fault

FAIL

Receiver fault

NHX–4N

OK

Transmitter operating

(RF power OK) ?

OK

Earphone level/

modulation

(nom, max)

OK

Is display/keypad
module working ?

OK

FAIL

FAIL

FAIL

Transmitter fault

Earphone level or
modulation fault

Display or keypad fault

Original, 01/98

END

OK

FAIL

Call set–up faultCall set–up ?

Page 7

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Logic fault

Logic fault

Power drops off or does
not assume local mode

OK

Check clock signal

of CLKMCU ~3.3 Vpp

FAIL

VL, VL2, VA and
VREF ~3.3 V or only

momentarily on

FAIL

Technical Documentation

Voltages always 3.3 V

FAIL

OK

XRES ~ 0 V

FAIL

OK

Check d.c. voltages
of N101;
– pin 17 ~1.75 V if
VBAT ~4.8 V
– pin 1, 5, 22 ~VBAT

Check;
– D201 pins 51 (CLKMCU), 21 and 53
(VL2), 67 and 68 (VREF), 12, 30,

50 and 58 (GND)

Check MBUS connection
d.c. voltages;
– D201/9 TXD ~3.3 V
– D201/10 RXD ~3.3 V
– X100/2 M2BUS ~3.3 V
Above lines are to show

to 3.3V all the time.

N101/14 XPWROFF line

at least 1 microsec. pulse to 3.3 V

3 sec. intervals (momentarily)

OK

OK

OK

FAIL FAIL

N101/13 PWRONX

line 0 V pulse (momentarily)

Check;
– solderings of MUUMI N101

– loading of supply voltages
– if OK, change N101

– Check load on VL2,

VA and VREF lines

Check;
– PWR button
– V930

– ROW0

– XPWROFF line (COL0) load

– If OK, change D201

Page 8

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

Receiver fault

Receiver fault

Simplex sens.

(TX off)

FAIL

See earphone level fault

N370/9 (DAF) OK?

OK

AF signal at

FAIL

VCCR, VREF,VSYN

OK?

FAIL

NHX–4N

Check: V310, V311

V313, V314,

N101/4

OK

TX spectrum

OK

Replace duplex
filter Z660

FAIL

Transmitter
fault

RX–VCO

oscillating

OK

VCO–freq

OK

FAIL

Check: operating voltage of
G530

Check: resistance through
N820/3, R521, R522, R523

FAIL

voltage N820/4,14
Connections of R530, C532
VCTCXO operating voltage

and frequency = 14.85 MHz.

Check SCLK, SDAT and SLE

lines.

OK

RXINJ

OK at V341
collector

FAIL

OK

at N370/16

FAIL

IF level

after Z350

FAIL

Check: solderings of
Z660, Z321, Z350
operation of V320

1. IF

OK?

OK

Check: voltage of N370/4,
components C378, R371,C377,

Z370, L370,
if OK replace N370

OK

Check operation
of V380

Check: RXINJ level at V341
collector (5–10 dBm), V341
operating voltage and bias, C341

Original, 01/98

Page 9

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Transmitter fault

Check: resistance through N820/17,R421, R422, R423

Transmitter fault

Transmitter
frequency

OK

OK

Connections of R430, C432.VCTCXO operating
voltage and freq. =14.85 MHz. Check SCLK,SDAT

and SLE lines.

FAIL

FAIL

TX–VCO

freq and spectrum

OK (TXE OFF)

OK

Technical Documentation

Buffer V430

output freq. and

spectrum OK
(TXE OFF)

OK

FAIL

Check: V430 operating
voltage and bias, C440
R440, C443

590<Pout<980 mW

(level High) at C642

OK

Check Z660 TX–pin
soldering. If OK replace
Z660

Check: R647, V642,R660

C643, VTSYN, TXE, TXC
R641, R655, R649, R640,
V650, V641, V640

FAIL

FAIL

Power OK after

tuning

FAIL

Vpc N601/1

2.5–3.5 V (level 1,2,3)

OK

TXINJ level

6–12 dBm after

Z601

FAIL

OK

OK

OK

Buffer V440

output freq. and

spectrum OK

(TXE ON)

OK

N601 freq.
and spectrum OK
when duplex filt.

not connected

FAIL

Check: C631, C641, C660
C642, C634, C635, C608
C625, C602. If Ok
replace N601.

FAIL

OK

Check: V440 operating
voltage and bias, C450,
R455, C454, TXE

Check soldering of duplex
filter Z660. If OK replace
filter.

Replace G430

Page 10

FAIL

VCO output

level –3...+3 dBm

OK

Check operation of V430
and V440

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

Audio fault

EARPHONE LEVEL / MODULATION LEVEL FAULT
SIGNAL LEVELS OF AUDIO CIRCUiT N701

MIC

PIN 46
XMIC

MICAM

50 mVrms

TXMUX+TXAAF

TXATT

MICTRI

ATTO

TXBP

ATTO
COMI
COMO
EMPI
EMPO
LPIN

COMI

PIN 47
PIN 49
PIN 50
PIN 51
PIN 52
PIN 53

COMPR

COMO

EMPI

50 mVrms
50 mVrms
70 mVrms
70 mVrms
95 mVrms
95 mVrms

EMPO LPIN

PREEM TXLP

LIM1 LIM2

TXTRI+TXPOSTFIL

WTRFIL+WPOSFIL

SUM

NHX–4N

MOD
PIN 55

170 mVrms

Signal levels are measured by oscilloscope and input signal frequency is 1 kHz. Transmitted signal deviation is 2.3 kHz.

HF CONTROL

VOL

RXTRI

PIN 27
DAF

125 mVrms

Signal levels are measured by oscilloscope. Received signal audio frequency is 1 kHz, deviation 5.7 kHz and power level –53dBm.

RXAAF EXP

RXMUX+AAFIL

DEEMP+RXFIL

FILOEXPI

EAMPBO

EXPO

VOLI

RXATT

EAR

ACC

FILO
EXPI
EAMPBO
EWCI PIN 31 100 mVrms
EXPO
VOLI
EARP
EARM
XEAR PIN 35 130 mVrms

PIN 28
PIN 29
PIN 30

PIN 32
PIN 34
PIN 38
PIN 37

EARP
EARM

EVGND

XEAR

180 mVrms
180 mVrms
100 mVrms

330 mVrms
330 mVrms
120 mVrms
120 mVrms

Original, 01/98

Page 11

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Display or keyboard fault

Display or keypad fault

FAIL

Lights OK ?

OK

KEYBOARD
FAULT

Display does’nt work

D201/29 LIGHTS
line at + V with
lights on

OK

Check operation of
switches V43 and V45

Pulses to 3.3V
on COL0–4 lines at
~50 ms intervals

FAIL

FAIL

Technical Documentation

Check load in lights line

(R920, R921, R922, R923, R924)

Check COL0–4 lines from
keyboard to D201

OK

Check pins

Pin 33 V5OUT ~–6.5 V

Pin 38 VCI ~3.3V

OK

Check pin

Pin 31 V5 ~–5.0V

OK

FAIL

FAIL

OK

ROW0–2 lines are to carry 3.3V
and pulses to 0 V at ~50 ms
intervals when corresponding
key depressed

clock signals

Pin 37 C1+ 3.3V/7.2kHz

Pin 35 C2+ 6.6V/7.2kHz

OK

Check soldered joints of D100

Check R901–904 and C902, C903

FAIL

Check components;
– C900, C901

Page 12

Check;
Display foil solder joints;
D100/40/LCDRES 3.3V

Original, 01/98

PAMS

Disassembly & Troubleshooting Instructions

Technical Documentation

Call set–up fault

Call set–up fault

Phone will not
assume SERV – mode

Subscriber data OK ?

OK

OK

FAIL

NHX–4N

Check subscriber data and country codes and
correct them if needed.

RSSI operative ?

OK

Data
detection of N701
operative ?

OK

Replace N701

FAIL

FAIL

Check RSSI tunings and tune if needed.
Check N370/12/RSSI–line and the operation

Inspect the signal path from test point DAF
to N701/27
Check also other lines to N701.

Original, 01/98

D0000123

Page 13

Disassembly & Troubleshooting Instructions

PAMS

NHX–4N

Technical Documentation

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Page 14

Original, 01/98