Motorola APX 3000

5-24 Troubleshooting Charts: TX Audio Error
5.7 TX Audio Error – External Mic Failure
TX Audio error
External MIC
Audio signal present?
Replace Backit Flex.
Measure MIC Bias at
R6404
Is Connector
Demaged or Soldered
improperly
Measure Audio at CODEC
C6404 Capacitor
Replace Connector
Check TX_DA thru R2817.
If no signal check CODEC
circuitry.
4.5 < V < 4.9
Inspect MIC Bias
circuit U6402 and
Supporting Circuitry
Parts Solder and
Placement Correct?
Is SSI Audio
Data Present
View SSI Signals at R2807
and R2808 using
Oscilloscope.
Check CODEC
or OMAP
Replace U6402
Replace parts
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No