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Nokia Customer Care
RH-19/RH-50 Series Cellular Phones
7 - RF Description and
Troubleshooting
Issue 3 05/2004 2004 Nokia Corporation. Page 1
Company Confidential
RH-19/RH-50 Company Confidential
7 - RF Description and Troubleshooting Nokia Customer Care
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Page 2 2004 Nokia Corporation. Issue 3 05/2004
Company Confidential RH-19/RH-50
Nokia Customer Care 7 - RF Description and Troubleshooting
Table of Contents
Page No
RF Description and Troubleshooting ................................................................................................... 5
Introduction ........................................................................................................................................... 5
RF key component placement ........................................................................................................... 7
RF test points ......................................................................................................................................... 8
Receiver ................................................................................................................................................. 8
Transmitter ........................................................................................................................................... 9
Synthesizer ........................................................................................................................................... 9
RF in General............................................................................................................................................10
RF power supply configuration .......................................................................................................12
General specifications of transceiver RH-19/RH-50 ................................................................13
Receiver Description and Troubleshooting......................................................................................14
General instructions for RX troubleshooting ..............................................................................14
Measuring RX I/Q signals using RSSI reading ..........................................................................14
Measuring RX performance using SNR measurement ...........................................................16
Measuring front-end power levels using spectrum analyzer...............................................19
Measuring analogue RX I/Q signals using oscilloscope.........................................................19
Fault finding chart of the receiver ................................................................................................21
RX signal paths ...................................................................................................................................23
Antenna switch (RX/TX switch) ....................................................................................................23
RX front-end ......................................................................................................................................24
RX paths of Mjoelner RF ASIC.......................................................................................................24
Transmitter Description and Troubleshooting ................................................................................25
General instructions for TX troubleshooting ..............................................................................25
TX signal paths ....................................................................................................................................25
Antenna switch (TX/RX switch) ....................................................................................................27
GSM (GSM850/900) transmitter ....................................................................................................27
General instructions for GSM850/GSM900 TX troubleshooting.........................................27
GSM1800 (DCS/PCN) transmitter ..................................................................................................31
General instructions for GSM1800 TX troubleshooting ........................................................31
Fault finding chart for GSM1800 transmitter..........................................................................33
GSM1900 (PCS) transmitter ............................................................................................................34
General instructions for GSM1900 TX troubleshooting ........................................................34
Fault finding chart for GSM1900 transmitter..........................................................................36
Synthesizer Description and Troubleshooting ................................................................................37
General instructions for synthesizer troubleshooting ..............................................................37
Check synthesizer operation ...........................................................................................................37
26 MHz reference oscillator (VCXO) .............................................................................................38
VCO .........................................................................................................................................................38
Fault finding chart for PLL synthesizer ........................................................................................39
Frequency lists .....................................................................................................................................41
GSM850 (RH-50) ..............................................................................................................................41
GSM900 (RH-19) ..............................................................................................................................42
GSM1800 (RH-19/RH-50)..............................................................................................................43
GSM1900 (RH-19/RH-50)..............................................................................................................44
DC supply current check ...................................................................................................................45
RF Tuning Instructions ..........................................................................................................................46
General instructions for RF tuning ................................................................................................46
Issue 3 05/2004 2004 Nokia Corporation. Page 3
RH-19/RH-50 Company Confidential
7 - RF Description and Troubleshooting Nokia Customer Care
RF tuning after repairs ......................................................................................................................46
RX calibration ......................................................................................................................................46
RX calibration GSM850/900..........................................................................................................47
RX calibration GSM1800 (DCS/PCN)...........................................................................................51
RX calibration GSM1900 (PCS).....................................................................................................53
RX band filter response compensation .........................................................................................56
RX band filter response GSM850/GSM900 ...............................................................................56
RX band filter response GSM1800 (DCS/PCN) .........................................................................58
RX band filter response GSM1900 (PCS) ...................................................................................61
RX channel select filter calibration ...............................................................................................65
RX AM suppression ............................................................................................................................65
TX power level tuning ........................................................................................................................66
TX power level tuning GSM850/GSM900 ..................................................................................66
TX power level tuning GSM1800 (DCS/PCN) ............................................................................68
TX power level tuning GSM1900 (PCS) ......................................................................................69
TX I/Q tuning ........................................................................................................................................71
TX I/Q tuning GSM850/GSM900 ..................................................................................................71
TX I/Q tuning GSM1800..................................................................................................................77
TX I/Q tuning GSM1900..................................................................................................................81
Appendices
Appendix A: FLALI Test Cases with Hints for Repair
Appendix B: FinUI Test Cases with Hints for Repair
Appendix C: Component Placement with Test Points and Detailed Description
Page 4 2004 Nokia Corporation. Issue 3 05/2004
Company Confidential RH-19/RH-50
Nokia Customer Care 7 - RF Description and Troubleshooting
RF Description and Troubleshooting
Introduction
The sections below provide instructions how to check, repair and calibrate the RF section
of RH-19/RH-50 phones.
It is assumed that for tuning and repair the phones are disassembled and tested within a
repair jig MJS-52.
The following types of measurements can be done for diagnosis and repair of RH-19/RH-
50 phone modules: