Rx Lb Troubleshooting - Nokia RM-761 Service Manual

RM-761; RM-799; RM-800
RF Troubleshooting
Figure 36 RX checkpoints and component overview (measurement point marked with blue)

RX LB troubleshooting

The test signal from GSM tester must be a continuous signal, as the phone has no means of synchronizing to
a GSM burst signal in local mode. To excite the RSSI detector in the same way a modulated GSM signal does,
the test signal must either be GMSK modulated (Pseudo-random bit sequence (PRBS)) or an un-modulated
CW-signal with 67.7kHz offset from center frequency.
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