3-12

SECTION3 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE

(2) No F.OSD display.

(3) No Key display

Is there 5.3V IC501 Pin 51?
NO
NO
Replace bad switches
Replace X502.

No Key display

Is there 5.2VA at IC501

Pin79, 80, 81?

YES
As pressing the byttons doeseach
function work properly?
YES
Check power circuit
Check 5.3V Line of power
circuity.
Does oscillation appear at the
IC501 Pins 40, 41?
NO
NO
NO
YES
Does oscillation appear at the
IC501 PIns 37, 38?
YES

Check peripheral circuit and

replace X501

YES

No OSD display.

6. OSD CIRCUIT

(1) No OSD display.

Does Video signal appear at the
IC501 Pin 47?
YES NO

Check the signal between

IC501 Pin47 and V.out Jack.

Replace IC501.
YES
Refer to “(5) No OSD picture”
Check the signal between IC301
Pin 29 and IC501 Pin 49.
YES
Check power Vcc 9V
Replace IC501
NO
NO
YES
Does video signal appear at
IC501 Pin 50?
YES

No F.OSD display.