Sharp 4T-B70CJ1U - Page 31

4T-B70CJ1 TROUBLE SHOOTING 4 - 29
2-5. No audio heard (1)
↓ Yes
NO
↓ 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 IC1702normal?
NO
Check IC1702 and its peripheral circuits.
Check speakers and their peripheral
circuits.
No sound in the UHF/VHF reception.
Is the IF output from the tuner pin(6,7,8,9)
of TU1102 as specified ?
Check TU1102 and its peripheral circuits.
Is there IF input at pin K1 & K2 of IC3301 ?
Check the circuit between TU1102 &
IC3301.
Is there audio 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.