Vocon Tx Audio Error - Motorola APX 5000 Service Manual

5-30
5.13 VOCON TX Audio Error – Backside Microphone
Backside Side Mic is
Inoperative
Isolate Problem,
Replace Backside
Mic
Is Backside Mic
Functional
No
Replace RF Board
Is Backside Mic
Functional
No
Measure Mic Bias
at R6403
4.5 < V <4.9?
Yes
Inspect SSI Audio
Data using
Oscilloscope at
R3016
Yes
Replace Backside
Mic
Yes
Replace RF Board
Inspect Mic Bias
No
Circuit U6402 and
Supporting
Circuitry
Is SSI Audio
Data Present
No
Replace VoCon
Board
Troubleshooting Charts: VOCON TX Audio Error
Synopsis
This failure specifically refers to the
backside 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
Connections and
Placement Correct
View SSI Signals
at R1017, R1007,
Yes
and R1008 Using
an Oscilloscope
No
Yes
Replace VoCon
Board
Yes
Is SSI RF Data
Present
No
Replace VoCon
Board
Repair or Replace
Connector
Yes
Is Connector
Damaged or
Soldered
Improperly
Examine
Connector J1001