Trouble Shooting Chart
No Analog Audio Output on Cinch
Check point: Pins 1,3,4 of U5
(2-Channel audio D/A converter)
Observe: Signal present at those pins
but no signal at pin8 and pin11
Check point: Q12 on decoder board
Observe: the stable low voltage presented
at BAS Terminal of Q12
Solution:
Check the IC U2 at front control board
Solution: Replace U20 (8728)
Solution: Replace U501
Solution:
Check the power supply circuit
GO
YES
Signal is presented
NO
NO
Video output is normal but
no analogue audio output
Check point: U501 at power board
Observe: the output voltage of U501
Check point: Q507 on power board
Observe: the voltage presented at
collector terminal of Q507
YES
YES
YES
4-5
LRCLK waveform
Audio_DL/Audio_DR(U2 PIN