Osd Circuit - LG TL-AT130M Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE
(3) No Key display
No Key display
YES
Is there 5.2VA at IC501
Pin79, 80, 81?
YES
As pressing the byttons doeseach
function work properly?

6. OSD CIRCUIT

(1) No OSD display.
No OSD display.
YES
Is there 5.3V IC501 Pin 51?
YES
Does oscillation appear at the
IC501 PIns 37, 38?
YES
Does oscillation appear at the
IC501 Pins 40, 41?
YES
Does Video signal appear at the
IC501 Pin 47?
YES
Replace IC501.
SECTION3 ELECTRICAL
NO
Check power circuit
NO
Replace bad switches
Check 5.3V Line of power
NO
circuity.
NO
Replace X502.
NO
Check peripheral circuit and
replace X501
NO
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"
YES
Does video signal appear at
IC501 Pin 50?
YES
Replace IC501
3-12
NO
Check power Vcc 9V
NO
Check the signal between IC301
Pin 29 and IC501 Pin 49.