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Nokia Customer Care
RH-21 Series Transceivers
Troubleshooting
Issue 2 07/2004 2004 Nokia Corporation. Page 1
Company Confidential
RH-21 Company Confidential
Troubleshooting Nokia Customer Care
Page 2 2004 Nokia Corporation. Issue 2 07/2004
Company Confidential RH-21
Nokia Customer Care Troubleshooting
Contents
Page No
Troubleshooting ............................................................................................................. 5
Baseband Troubleshooting ..........................................................................................5
General testing information....................................................................................... 5
Troubleshooting ........................................................................................................ 6
Phone does not start up normally or does not stay on............................................... 8
Flash Programming does not work.......................................................................... 10
Charging .................................................................................................................. 12
Audio failures.......................................................................................................... 13
Accessory detection................................................................................................. 15
Sleep Clock ............................................................................................................. 16
User Interface .......................................................................................................... 18
Receiver Troubleshooting ..........................................................................................20
General Instructions for RX troubleshooting .......................................................... 20
Path of the received signal ...................................................................................... 20
Fault-finding charts for receiver chain .................................................................... 21
Transmitter fault-finding ...........................................................................................29
General instructions for TX troubleshooting .......................................................... 29
Path of the transmitted signal .................................................................................. 29
Fault-finding charts for transmitter ......................................................................... 29
Power control loop .................................................................................................. 32
Synthesizer fault-finding ...........................................................................................35
19.44 MHz reference oscillator ............................................................................... 35
RX VHF VCO......................................................................................................... 37
TX VHF VCO ......................................................................................................... 38
UHF Synthesizer ..................................................................................................... 38
Issue 2 07/2004 2004 Nokia Corporation. Page 3
RH-21 Company Confidential
Troubleshooting Nokia Customer Care
Page 4 2004 Nokia Corporation. Issue 2 07/2004
Company Confidential RH-21
Nokia Customer Care Troubleshooting
Troubleshooting
The first thing to do when a problem is encountered is to carry out a thorough visual
check of the module. Make sure that: