Preparing For Synthesizer Troubleshooting - Nokia RM-51 Service Manual

RM-51
RF troubleshooting
Other filter components are for sideband rejection.
The dividers are controlled via the RFBus. RFBusData is for the data, RFBusClk is a serial clock for the bus and
RFBusEna1X is a latch enable, which stores the new data into the dividers.
Assumption
• No soldering or component failure for simple SMD components such as resistors, inductors and capacitors
• Failure in one particular operating GSM channel, whether Tx or Rx, in which the synthesizer is the cause of
the failure, causes failure in all other GSM channels in Tx/Rx.

Preparing for synthesizer troubleshooting

Steps
1. Place the phone (mechanics removed) on module jig.
2. Connect the module jig to the PC via a DAU-9P cable.
3. Connect the module jig to a power supply (4.2V).
4. Connect the RF output to a spectrum analyzer or another measurement instrument.
5. Use a 10dB attenuator at the input to spectrum analyzer to avoid damage.
6. Make sure the dongle is connected and start Phoenix.
7. In Phoenix, select File -> Open Product -> RM-51 (Nokia 3230) Product Menu.
8. Select Testing -> RF Controls.
9. In the toolbar: set Operating Mode -> Local.
10. Select Band -> GSM 1800.
11. Set Operation Mode -> Continuous.
12. Set Active Unit -> Rx.
9238460 (Issue 1)
Figure 154 Synthesizer key components
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