Audio Circuit - LG TL-AT130M Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

4. AUDIO CIRCUIT

(1) No sound in EE Mode
No sound in EE Mode.
YES
No sound.
YES
Is 5V applied to the IC301
Pin 75?
YES
Is the Audio signal applied to the
IC301 Pin 76?
YES
Does the Audio signal appear
at the IC301 Pin 96?
YES
Check the connection of the Audio
out Jack.
YES
2
Does the CLK/Data signal(I C)
appear at the IC301 Pin 23, 24?
YES
Replace the IC301
SECTION3 ELECTRICAL
NO
Check the line of the 5V Line.
(Power Circuit)
NO
Check the path of
LINE/AUDIO.
NO
Is the Audio Mute "High" signal applied
to the IC301 Pin 10?
NO
YES
Check the IC501 Pin 2.
(Audio Mute "H".)
Check the IC501 Pin18(CLK),
NO
17(Data) Line.
(2) No sound in PB MODE
No sound in PB Mode.
YES
No sound.
YES
Is 5V applied to the
IC301 Pin 75?
YES
2
Does the CLK/Data signal(I C)
appear at the IC301 Pin 23, 24?
YES
Does the Audio signal appear
at the IC301 Pin 1?
YES
Does the Audio signal appear
at the IC301 Pin 96?
NO
Replace the IC301
3-9
NO
Check the line of the 5V Line.
(Power Circuit)
NO
Check the IC501 Pin 18(CLK),
17(Data) Line.
NO
Check the connecting State between
the P3D02 Pin 6 and A/C Head.
YES
Is the Audio Mute "H" applied to
the IC301 Pin 10?
NO
YES
Check the IC501 Pin2.