SECTION3 ELECTRICAL

ELECTRICAL TROUBLESHOOTING GUIDE

(3) No Key display

No Key display

YES

Is there 5.2VA at IC501

NO

 

 

 

Pin79, 80, 81?

 

 

 

 

 

 

 

 

 

YES

 

 

NO

 

 

 

 

As pressing the byttons doeseach

 

 

 

function work properly?

 

 

 

 

 

 

 

 

 

 

 

 

Check power circuit

Replace bad switches

6. OSD CIRCUIT

(1) No OSD display.

No OSD display.

YES

Is there 5.3V IC501 Pin 51?

 

NO

 

 

 

 

 

YES

NO

Does oscillation appear at the

IC501 PIns 37, 38?

YESNO

Does oscillation appear at the

IC501 Pins 40, 41?

YES

NO

Does Video signal appear at the

IC501 Pin 47?

YES

Replace IC501.

Check 5.3V Line of power circuity.

Replace X502.

Check peripheral circuit and replace X501

Check the signal between IC501 Pin47 and V.out Jack.

(2) No F.OSD display.

No F.OSD display.

YES

Refer to “(5) No OSD picture”

 

NO

 

 

 

 

 

YES

NO

Does video signal appear at

IC501 Pin 50?

YES

Replace IC501

Check power Vcc 9V

Check the signal between IC301 Pin 29 and IC501 Pin 49.

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LG Electronics TL-AT130M service manual No Key display, OSD Circuit, No OSD display, No F.OSD display