Sharp 4T-B70CJ1U - Page 32

4T-B70CJ1 TROUBLE SHOOTING 4 - 30
2-6. No audio heard (2)
No external audio heard<INPUT3>
Is there the L-ch audio signal input from pin
(4) of input terminal J502 to pin (D4)
ofIC3301?
Is there the R-ch audio signal input from pin (1) of
inputterminal J502 to pin (D5) of IC3301?
↓ Yes
NO
↓ Yes
NO
↓ Yes
↓ Yes
NO
↓ Yes
Is the L-ch audio signal output at
pin(8),(9),(12),(13) of IC1702 normal ?
Is the R-ch audio signal output at
pin(18),(19),(22),(23) of IC1702 normal ?
NO
Check IC1702 and its peripheral circuits.
Check speakers and their peripheral circuits.
Is there the signal output at pin
(AL28),(AL27),(AK28), (AM27) of IC3301 ?
Check IC3301 and its peripheral circuits.
Is there signal input at pin(1),(2),(3),(4) of
IC1702?
Check connection between IC3301 and
IC1702 and its peripheral circuits.
Are the audio signal L-ch and R-ch output at
(3)/(4) and (1)/(2) of P504 normal?
Check circuit between IC1702 & P504.