Nokia 2650 Service Manual page 160

RH-53/54
Baseband Troubleshooting................................................................................ 5
Baseband test points ......................................................................................... 5
Troubleshooting diagrams ................................................................................. 6
Phone is dead .................................................................................................... 7
Flash programming does not work..................................................................... 8
Power does not stay on or phone is jammed..................................................... 9
Display information : "Contact Service"............................................................ 10
The phone does not register to the network, or the phone cannot make a call 11
Charging troubleshooting................................................................................. 12
Audio troubleshooting 1, 2 ............................................................................... 14
Audio troubleshooting 3: Headset does not work ............................................ 15
Upper block failures.......................................................................................... 16
Introduction to RH-53/54 RF Troubleshooting ............................................... 21
General description of the RF circuits ............................................................ 22
Receiver signal path ........................................................................................ 22
Transmitter signal path .................................................................................... 22
PLL................................................................................................................... 23
RF Key component placement......................................................................... 26
Troubleshooting................................................................................................ 27
Common circuit ................................................................................................ 27
Power Supply Configuration .......................................................................... 27
General instructions for Synthesizer troubleshooting ...................................... 29
26 MHz Reference Oscillator ( VCXO ) ........................................................... 29
Example Signal Measured at VCXO output (R420) ....................................... 30
VCO ............................................................................................................... 30
Troubleshooting chart for the Synthesizer ....................................................... 31
Measurement points for the Synthesizer ......................................................... 32
Receiver Troubleshooting ............................................................................... 35
Front End Module (FEM) control signals ......................................................... 35
Renesa FEM logic .......................................................................................... 35
RFMD FEM logic ............................................................................................ 35
Measurements points....................................................................................... 36
Measurement points for the receiver ............................................................. 36
RH-54 Receiver ............................................................................................... 38
General Instructions for GSM850 RX Troubleshooting .................................. 38
General Instructions for GSM1900 RX Troubleshooting.................................. 41
RH-53 Receiver ............................................................................................... 44
General Instructions for GSM900 RX Troubleshooting .................................. 44
General Instructions for GSM1800 RX Troubleshooting ................................ 46
RH-53/54 Transmitter Troubleshooting........................................................... 51
Measurement points for the transmitter ........................................................ 51
Issue 2 06/2005 COMPANY CONFIDENTIAL
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