Function Mode Audio Abnormal - LG DM5420K Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

3. FUNCTION MODE AUDIO ABNORMAL

AUX abnormal
Check the signal input
of IC112 pin5, 14.
Check the signal input circuit
(L401,L402,L403,R416,R417,R418,R435,C430, C431).
Check the signal input JK101 pin1, 3.
Normal.
Tuner abnormal
Check the signal input of IC112 pin1, 12.
Check the signal output
of TU400 pin1, 2.
Check TU400
VCC normal?
Check the VCC power circuit.
YES
NO
NO
NO
YES
NO
NO
NO
YES
YES
R400, R401, R402, R403, C402, C403.
YES
pin4 "TU_CK", pin5 "TU_DA", pin7 "TU_RST".
3-5
OK
Check
Check TU500
YES
Normal