LG DP381B Service Manual page 21

MAIN ELECTRICAL TROUBLESHOOTING GUIDE
B. AUDIO OUT ABNORMAL
Audio out abnormal
YES
Check Audio jack & mode
YES
Check +5V
YES
Check signals from MPEG
YES
Replace IC(U2)
D. AUDIO IN/SPEAKER ABNORMAL
Audio in/speaker
abnormal
YES
Check Audio jack &
mode S/W
YES
NO
Is Q4
and Q6 OK.
YES
NO
Is speakers OK.
Replace
YES
Replace IC(U3)
LGE Internal Use Only
Replace
Q4 and Q6
Replace Speakers
3-12
C. VIDEO OUT ABNORMAL
Video out abnormal
YES
Check Video jack & mode
YES
Check Video signals from MPEG
YES
Check IC(U1)
E. VIDEO IN ABNORMAL
Video in abnormal
YES
Check Video jack
& mode
YES
NO
Is U1 OK.
YES
Check
R250, R251, C112
YES
Refer to LCD part
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Only for training and service purposes
Replace (U1 IC)