Nokia NPL-4 Series Guide

Nokia Customer Care
NPL-4/5/RM-104 Series Transceivers
Issue 2 05/05 Copyright © 2005 Nokia Corporation. All rights reserved.
Troubleshooting Instructions

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Troubleshooting Instructions Nokia Customer Care
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Table of Contents
Page No
RF Troubleshooting ....................................................................................................... 7
Introduction to RF troubleshooting .............................................................................7
RF Key component placement .....................................................................................8
RF Test Points................................................................................................................ 9
Receiver .....................................................................................................................10
Transmitter .................................................................................................................11
Synthesizer .................................................................................................................11
RF in General............................................................................................................... 12
RF Power Supply Configuration.................................................................................. 14
Receiver Verification and Troubleshooting................................................................. 16
General instructions for RX troubleshooting .............................................................16
Measuring RX I/Q Signals using RSSI Reading..................................................... 16
Measuring RX performance using SNR measurement ........................................... 18
Measuring front-end power levels using spectrum analyzer................................... 19
Measuring analogue RX I/Q signals using oscilloscope......................................... 20
Fault finding chart of the receiver........................................................................... 21
Rx signal paths ...........................................................................................................25
Antenna switch (RX/TX switch)............................................................................. 25
Rx front-end ............................................................................................................ 26
RX paths of RF ASIC.............................................................................................. 27
Transmitter................................................................................................................... 28
General instructions for transmitter troubleshooting .................................................28
Transmitter troubleshooting .......................................................................................28
Antenna switch (TX/RX switch)............................................................................. 28
GSM850 transmitter ..................................................................................................29
General instructions for GSM850 TX troubleshooting........................................... 29
GMSK ..................................................................................................................... 29
EDGE...................................................................................................................... 30
Fault Finding Chart for GSM850 Transmitter ........................................................ 32
GMSK ..................................................................................................................... 33
EDGE...................................................................................................................... 34
GSM900 transmitter ..................................................................................................34
General instructions for GSM TX troubleshooting................................................. 34
GMSK ..................................................................................................................... 34
EDGE...................................................................................................................... 35
Fault finding chart for GSM900 transmitter ........................................................... 36
GMSK ..................................................................................................................... 37
EDGE...................................................................................................................... 38
GSM1800 transmitter ................................................................................................38
General instructions for GSM1800 TX troubleshooting......................................... 38
GMSK ..................................................................................................................... 38
EDGE...................................................................................................................... 39
Fault finding chart for GSM1800 transmitter ......................................................... 40
GMSK ..................................................................................................................... 41
EDGE...................................................................................................................... 42
GSM1900 transmitter ................................................................................................42
General instructions for GSM1900 TX troubleshooting......................................... 42

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GMSK ..................................................................................................................... 42
EDGE...................................................................................................................... 43
Fault finding chart for GSM1900 transmitter ......................................................... 44
GMSK ..................................................................................................................... 45
EDGE...................................................................................................................... 46
Synthesizer................................................................................................................... 47
Check synthesizer operation ......................................................................................47
Reference oscillator 26 MHz (VCTCXO) .................................................................48
Voltage Controlled Oscillator (VCO) ........................................................................49
Fault finding chart for PLL synthesizer .....................................................................50
Pictures of synthesizer signals ...................................................................................51
Frequency tables ........................................................................................................53
GSM850.................................................................................................................. 53
GSM900 (including EGSM900) ............................................................................. 54
GSM1800................................................................................................................ 55
GSM1900................................................................................................................ 57
DC Supply Current Check ........................................................................................... 59
Baseband Troubleshooting........................................................................................... 60
BB measurement points .............................................................................................60
Troubleshooting diagrams .........................................................................................62
Phone is dead. ............................................................................................................63
Phone is jammed 1 .....................................................................................................64
Phone is jammed 2 .....................................................................................................65
Flash faults 1 ..............................................................................................................66
Flash faults 2 ..............................................................................................................67
SIM card faults ..........................................................................................................68
Charger faults .............................................................................................................69
Display faults 1 ..........................................................................................................70
Display faults 2 ..........................................................................................................71
Audio fault1 ...............................................................................................................72
Audio fault 2 ..............................................................................................................73
Audio fault 3 ..............................................................................................................74
Keyboard faults 1 .......................................................................................................75
Keyboard faults 2 .......................................................................................................76
Keyboard faults 3 .......................................................................................................77
Keyboard faults 4 .......................................................................................................78
Keyboard faults 5 .......................................................................................................79
Accessory faults1 .......................................................................................................80
Accessory faults 2 ......................................................................................................82
Flashlight faults .........................................................................................................84
Self tests .....................................................................................................................85
FCI troubleshooting ...................................................................................................86
IHF troubleshooting ...................................................................................................88
Compass Troubleshooting............................................................................................ 89
Calibration 1 ..............................................................................................................90
Calibration 2 ..............................................................................................................91
Sensor problems 1 ......................................................................................................92
Start calibration ..........................................................................................................93

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Magic troubleshooting ...............................................................................................96
FM Radio Troubleshooting.......................................................................................... 97
FM radio component layout .......................................................................................97
FM radio troubleshooting diagram ............................................................................99
Notes to "FM radio troubleshooting diagram"........................................................ 99
List of Figures
Page No
Fig 1 Component placement 1.............................................................................................8
Fig 2 Picture of the Assembled PWB with Chambers.........................................................9
Fig 3 Receiver Test Points...................................................................................................10
Fig 4 Transmitter Test Points...............................................................................................11
Fig 5 Synthesizer Test Points...............................................................................................11
Fig 6 RF Block -Diagram ....................................................................................................12
Fig 7 RF Power Supply Configuration ................................................................................13
Fig 8 RSSI Window.............................................................................................................17
Fig 9 Signal Measurement...................................................................................................19
Fig 10 Signal Amplitudes ....................................................................................................20
Fig 11 RX IQ Signals...........................................................................................................21
Fig 12 Receiver Fault Chart 1..............................................................................................22
Fig 13 Receiver Fault Chart 2..............................................................................................23
Fig 14 Receiver Fault Chart 3, 4, 5 .....................................................................................23
Fig 15 Receiver Fault Chart 6..............................................................................................24
Fig 16 Receiver Fault Chart 7..............................................................................................24
Fig 17 Receiver Fault Chart 8..............................................................................................25
Fig 18 Receiver Fault Chart 9..............................................................................................25
Fig 19 Block Diagram of Antenna Switch: Left Input Port (Antenna) and Right Output Ports
Rx/Tx .....................................................................................................................................26
Fig 20 RF Controls ..............................................................................................................30
Fig 21 RF Controls ..............................................................................................................32
Fig 22 Band Selection..........................................................................................................35
Fig 23 RF Control Values....................................................................................................36
Fig 24 RF Control Values....................................................................................................39
Fig 25 RF Control Values....................................................................................................40
Fig 26 RF Control Values....................................................................................................43
Fig 27 RF Control Values....................................................................................................44
Fig 28 Typical Feature Tuning Curve for the Matshushita VCO........................................48
Fig 29 26 Mhz at G501 Pin Out...........................................................................................51
Fig 30 26 MHz RFCLK at R420/C420................................................................................51
Fig 31 VCO Output, 1800 Band, RX on, Continuous Output.............................................52
Fig 32 DC Power Supply Diagram......................................................................................59
Fig 33 NPL-4/5 BB Measurement Points, Top ...................................................................60
Fig 34 NPL-4/5 BB Measurement Points, Bottom..............................................................61
Fig 35 MBUS.......................................................................................................................81
Fig 36 ACI Diagram ...........................................................................................................83
Fig 37 Testpoints .................................................................................................................94
Fig 38 Component placement .............................................................................................97
Fig 39 Trace layout.............................................................................................................98

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Fig 40 FM radio block layout. .............................................................................................98
Fig 41 FM radio troubleshooting diagram...........................................................................100
Fig 42 Oscilloscope screen shot, Audio output ...................................................................101
Fig 43 FM radio clock from test point J359, 32 kHz frequency clock signal, when radio is on.
102
Fig 44 FM frequency from FM radio pin 37, the other end of L358, with FM test signal..102
Fig 45 VCO frequency from FM radio pins 3 and 4, the other ends of V356 and V357, with
FM test signal.........................................................................................................................102

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RF Troubleshooting
Introduction to RF troubleshooting
Measurements should be done using Spectrum analyzer with high-frequency high-
impedance passive probe (LO-/reference frequencies and RF power levels) and Oscillo-
scope with a 10:1 probe (DC-voltages and low frequency signals)
The RF-section is built around one RF-ASIC (Helgo N500). For easier troubleshooting, this
RF troubleshooting document is divided in to sections.
Before changing Helgo, please check following things: Supply voltages are OK and serial
communication is coming from baseband to Helgo.
Please note that the grounding of the PA module is directly below PA-module so it is dif-
ficult to check or change. Most RF semiconductors are static discharge sensitive! So
ESD protection must be taken care of during repair (ground straps and ESD soldering
irons). Helgo and PA are moisture sensitive so parts must be pre-baked prior to soldering.
Apart from key components described in this document here are a lot of discrete compo-
nents (resistors, inductors and capacitors) which troubleshooting is done by checking if
soldering of the component is done properly (for factory repairs checking if it is missing
from PWB). Capacitor can be checked for shortening and resistors for value by means of
an ohmmeter, but be aware in-circuit measurements should be evaluated carefully.
Please be aware that all measured voltages or RF levels in this document are rough fig-
ures. Especially RF levels varies due to different measuring equipment or different
grounding of the used probe. When using RF probe usually a good way is to use metallic
tweezers to connect probe ground to PWB ground as close to measurement point as pos-
sible.

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RF Key component placement
Figure 1: Component placement 1

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RF Test Points
The RF power supplies are generated in the UEM and can be measured either in the Small
Signal Chamber or in the Baseband Chamber. On the drawings below small points show
the locations of the test points.
Figure 2: Picture of the Assembled PWB with Chambers

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Receiver
Figure 3: Receiver Test Points