Motorola APX 5000 Service Manual page 137

Troubleshooting Charts: VOCON TX Audio Error
5.14 VOCON TX Audio Error – External Mic Failure
TX Audio error
External Mic
Examin Vocon
and GCAI connector
on Expansion
Board
Is either Connector
Damaged or Soldered
Improperly
Measure Audio at
Vocon C6404
capacitor
Audio Signal
Present?
Measure Mic
Bias at R6404
4.5 < V < 4.9?
Test Internal
Side Mic
Measure Audio
Signal at Expansion
Board R2003
and L2002
No
Audio Signal
Present
Replace Housing
and GCAI Board
No
Replace or Repair
Connector
Yes
Yes
Replace Expansion
Board
No
Inspect SSI
Audio data at
R3016
Yes
Inspect Mic Bias
circuit U6402 and
Supporting Circuitry
No
Internal Side
Mic Funcional
Yes
Yes
Replace or Repair
Connector
Yes
Connector
Damaged?
Inspect Connector
J1001
Yes
Is SSI RFData
Present?
View SSI Signals
at R1017, R1007
and R1008 using
Oscilloscope
Yes
SSI Audio Data
Present?
Parts Solder and
Placement Correct?
Follow Vocon TX
No
Audio Error - Side
Mic Failure
Replace
No
Vocon Board
Replace
No
Vocon Board
No
Replace
Vocon Board
Yes
Replace or Replace
Parts
No
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