Checking The Audio Operation - NEC AccuSync LCD71VM Service Manual

9. Checking the Audio Operation

Is there Audio ON, Volume is tuned to Max when enter OSD function ,and Audio input signal.
Is there +5V supply on U501 pins 6, 16, 27.
NG
OK
Check Audio_Volume signal of equal" H " at U501 pin 7.
NG
OK
Check STBY. Is there +5V supply on U501 pin 2.
NG
OK
Check MUTE. Is there 0V on U501 pin 5.
NG
OK
Failure point
U501 failure.
Failure point
L501 open.
Check the trace from U501 pin 7 to U405 pin 24.
Failure point
1. Check software.
2. U405 failure.
Failure point
1. Check software.
2. U405 failure.
6-12
Failure point