Kara Section - Sony BDP-S485 Service Manual

Kara Section Flowchart
MIC does not work
Check voltage supply to all ICs:
No
IC401:Pin 8(AU_12V), Pin 4(AU_-12V)
IC402:Pin 8(AU_12V), Pin 4(AU_-12V)
IC403:Pin 8(AU_12V),
IC404:Pin 8(AU_12V)
IC904:Pin 8(AU_12V), Pin 4(AU_-12V)
Yes
Check XMIC signal,is there 0.6V at Pin 3,CN401
Yes
Check Mic Mute Signal, is there 3.3V at R972?
Yes
Check IFCON_MUTE Signal, is there 3.3V atR996?
Check the fuse, have the fuse blown?
replace MB board:PS901
Yes
No
Replace blown fuse. Symptom improve?
No
Replace Q402.Symptom improve?
No
Check R1602, is there 3.3V?
No
Replace IC1203.
Symptom improve?
To Power Supply (System) flowchart
No Replace Q401,Q402.
No
Replace IC401,IC402.
Symptom improve?
Symptom improve?
No
Replace the MB Board
No
Replace the MB Board
No
Replace the MC Board