Motorola ASTRO Digital Spectra Plus Detailed Service Manual page 237

Troubleshooting Charts
Verify Standard Bias per
Table (xref to standard operating bias table)
No
Standard Bias
OK?
Yes
Measure waveform at R428,
should match Figure 6-11
Waveform No
OK?
Yes
Measure waveform at TP401,
should match Figure 6-12
Waveform No
OK?
Yes
Measure waveform at C326,
Note: Amplitude
should match Figure 6-12
may be lower
than Figure
No
Waveform
OK?
Yes
Refer board to
Service Depot
6881076C25-E
See Chart C.26
Make sure the following
components are placed
OK?
and soldered correctly:
U408, Y401, R427, R425, R426,
C423, C424, C422
No
Repair proper
components
Make sure the following
components are placed
OK?
and soldered correctly:
Y400, U409, R456, R441, R442,
R435, R436, C420, R421, R430,
R443, C439, L400, C427
No
Repair proper
components
Make sure C326 is placed
OK?
and soldered correctly
No
Repair C326
Yes
Fixed?
Replace Y401
Yes
END
Yes
Fixed?
Repair Y400
Yes
END
Yes
Refer board to
Service Depot
No
Replace U408 Fixed?
Yes
END
No
Fixed?
Replace U409
Yes
END
Chart C.25 ASTRO Spectra Plus VOCON Power-Up Failure
5-19
No
Refer board to
Service Depot
No
Refer board to
Service Depot
September 5, 2008