204 Diagnosis of Faults on Main Board TM8100 Mobile Radio Service Manual
May 2004 © Tait Electronics Limited
Task 5 —
Incorrect RSSI Readings
If the RSSI readings are incorrect, use the calibration application to
check the receiver calibration as follows:
1. Open the “Raw Data” page and click the “Receiver” tab. Note the
settings listed in the “AGC Voltage Cal Pts” field. The nominal
settings should be as listed in Table 9.4. If the settings are correct,
go to Step 3. If they are not, recalibrate the receiver and check the
settings again. If they are now correct, go to Step 2. If they are
not, go to Task 1 and check the receiver sensitivity.
2. Check if the RSSI fault has been removed. If it has, return to
Subsection 8.1. If it has not, go to Step 3.
3. Note the settings listed in the “FE Tune BPF Settings” field. The
nominal settings should be as listed in Table 9.3. If the settings are
correct, go to Step 5. If they are not, recalibrate the receiver and
check the settings again. If they are now correct, go to Step 4. If
they are not, go to Task 1 and check the receiver sensitivity.
4. Check if the RSSI fault has been removed. If it has, return to
Subsection 8.1. If it has not, go to Step 5.
5. Note the values listed in the “RSSI Delta Gain Values” field. The
values should run gradually from 0 dB to about –3 dB. If they do,
go to Step 7. If they do not, recalibrate the receiver and check the
values again. If they are now correct, go to Step 6. If they are not,
go to Task 1 and check the receiver sensitivity.
6. Check if the RSSI fault has been removed. If it has, return to
Subsection 8.1. If it has not, go to Step 7.
7. Note the values listed in the “AGC Delta Gain Values” field. The
values should be between 0 dB and about 35 dB. If they are, go
to Step 9. If they are not, recalibrate the receiver and check the
values again. If they are now correct, go to Step 8. If they are not,
go to Task 1 and check the receiver sensitivity.
8. Check if the RSSI fault has been removed. If it has, return to
Subsection 8.1. If it has not, go to Step 9.
9. In this case all the RSSI calibration settings are correct, but there
is still an RSSI fault; go to Task 1 and check the receiver sensitivity.
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