SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

4. AUDIO CIRCUIT

(1) No sound in EE Mode

(2) No sound in PB MODE

No sound in EE Mode.

YES

No sound.

YES

Is 5V applied to the IC301

Pin 75?

NO

Check the line of the 5V Line. (Power Circuit)

No sound in PB Mode.

YES

No sound.

YES

Is 5V applied to the

NO

IC301 Pin 75?

 

 

 

 

Check the line of the 5V Line. (Power Circuit)

YES

Is the Audio signal applied to the

NO

 

Check the path of

 

 

IC301 Pin 76?

 

 

 

LINE/AUDIO.

 

 

 

 

 

 

 

 

YES

YES

 

 

NO

 

 

 

 

2

Does the CLK/Data signal(I C)

 

 

appear at the IC301 Pin 23, 24?

 

 

 

 

 

 

 

YES

NO

Check the IC501 Pin 18(CLK),

17(Data) Line.

Does the Audio signal appear

at the IC301 Pin 96?

YES

Check the connection of the Audio

out Jack.

NO

NO

Is the Audio Mute "High" signal applied

to the IC301 Pin 10?

YES

Check the IC501 Pin 2.

(Audio Mute "H".)

Does the Audio signal appear

at the IC301 Pin 1?

YES

Does the Audio signal appear

at the IC301 Pin 96?

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?

YES

NO

NO

YES

Does the CLK/Data signal(I2C) appear at the IC301 Pin 23, 24?

YES

NO

Check the IC501 Pin18(CLK),

17(Data) Line.

Replace the IC301

 

Check the IC501 Pin2.

 

 

 

Replace the IC301

3-9

Page 19
Image 19
LG Electronics TL-AT130M service manual Audio Circuit, No sound in EE Mode No sound in PB Mode