Panasonic SA-MAX3500PU Service Manual page 24

7.4. No Sound from MIC at any selector
Press Power Button of Unit
or Remote Control to Turn
ON the Unit
Select USB A selector, connect MIC1/
MIC2. Turn ON MIC and speak into MIC.
No Sound comes out from speaker.
-Check Mic and
Mic cable.
Check Supply
Voltage
IC1400/1
(pin9) >9V - OK
Check CN1401(pin 2/3)
Mic Det status when MIC
inserted, 3.3V OK
<2.0V - NG
Monitor CN1401 pin 1
(MIC IN) signal. No
Signal when speaking -
> NG
Check if signal at
main pcb C1048 to
IC1001
1
NG
Change Mic cable/
Mic if found NG.
OK
2
NG
Change IC1400/1
if found short to
gnd.
OK
3
Replace MIC
NG
Jacks
JK1401/
JK1403
OK
4
No
Replace:
Signal
IC1400/1
Yes
5
Replace
No
C1048 on
signal
Main PCB
Yes
Check SOC
IC1001
(Pin 84)
Yes
End
24
6
Change
No
IC1001.
signal