LG LHB976 Service Manual page 120

MAIN SET TROUBLESHOOTING
1-5. NO AUDIO OUTPUT
Optical function
YES
IC201
pin6 OPT_IN signal
OK?
YES
IC201
pin26 ~ 29 I2S signal
OK?
YES
IC401
Pin23, 24, 26, 27, 29, 30
signal OK?
YES
CN401
pin13, 14, 15 signal
OK?
YES
Update new wireless, μ-COM firmware.
Portable function
YES
CN253
pin6, 8 audio L/R
OK?
YES
IC401
Pin23, 24, 26, 27, 29, 30
signal OK?
YES
CN401
pin13, 14, 15 signal
OK?
YES
Update new wireless, μ-COM firmware.
NO
Check JK203 or replace.
NO
Check IC201 or replace.
NO
Check IC401 or replace.
NO
Check IC404 or replace.
NO
Check CN902, JK902.
NO
Check IC401 or replace.
NO
Check IC404 or replace.
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