5.12 Tx Audio Error - Motorola APX 1000 Detailed Service Manual

5-30

5.12 TX Audio Error

Internal Microphone
Rear MIC is
inoperative
Isolate problem, replace rear mic
Is rear mic functional
No
Measure Mic Bias at R6403
4.5 < V < 4.9
Yes
Inspect SSI_Red_Tx_Codec
audio data to OMAP by using
Oscilloscope at R6118.
Yes
Replace Rear
Mic
Inspect MIC Bias Circuit
No
U6402 and Supporting
Circuitry
Is SSI Audio
Data Present
No
Replace Main Board
Troubleshooting Charts: TX Audio Error
Synopsis
This failure specifically refers to the rear microphone
but this flowchart can be used to diagnose front side
microphone also. All mics mentioned above have
similar paths and have very limited differences.
Please refer to schematic and theory of operation
section for differences
Replace or Repair
Parts.
No
Are Parts Solder
Connectons and
Placement Correct
View SSI Signals
Yes
at R2819, R2807, and
R2808 using an Oscilloscope
Yes
Replace Main Board
Replace Main Board