Panasonic SA-MAX3500PU Service Manual page 22

7.3. No Sound at USB selector Only
Press Power Button of Unit
or Remote Control to Turn
ON the Unit
Select USB A or USB B selector,
connect USB device, play source.
No Sound comes out from speaker
Check IC1202
pin28(USB-A) or
pin27(USB-B)
High (3.3V) OK
Check
IC9002/IC9003
pin 1= 5V?
(pin 21)
Check IC4001
PWM output signal
(pin 27-34)
Check SOC
IC1001
(Pin 81, 82, 83,
84)
End
1
Yes
No
Change:
RX1207
Yes
2
No
Change:
IC9002 (USB-A)
IC9003 (USB-B)
Yes
3
No
Change
DSP
IC4001
Yes
4
No
Change series
resistors R1011,
R1012, R1023,
R1014, or
IC1001
22