LG 773E, CB773F-EA, CB773F-NA TROUBLESHOOTING GUIDE

TROUBLESHOOTING GUIDE

- 15 -

NO POWER

(POWER INDICATOR OFF)

TROUBLE IN
D900

TROUBLE IN FUSE
(F901)

TROUBLE IN
IC901

TROUBLE IN
D941, D942, D951,
D961, D962, D971

TROUBLE IN

Q903, Q972, Q971,

Q952, Q942, Q941

CHECK

FUSE OK?

CHECK

C908 VOLTAGE?

(AC120V: 160VDC,

AC220V: 304VDC)

NO

YES

YES

YES

YES

NO

NO

NO

CHECK

IC901 PIN 6

WAVEFORM

(SQUARE WAVE

COMES OUT?)

CHECK

D941, D942, D951,

D961, D962, D971

VOLTAGE?

1. NO POWER

- 16 -

2. NO CHARACTER

NO CHARACTER

CHECK

IC302

PIN 9(5V) ?

CHECK

IC302 PIN 5, 6, 7?

CHECK

IC302 PIN 20, 19, 18 ?

CHECK

IC303

PIN 1, 2, 3 ?

CHECK

IC303 PIN 4 (80V)

PIN 8 (12V) ?

TROUBLE IN
P302 5V LINE

TROUBLE IN
PC SIGNAL,
P301 SIGNAL CABLE

TROUBLE IN
IC302

TROUBLE IN
P303 12V LINE/
80V LINE

TROUBLE IN IC303

NO

YES

NO

NO

YES

YES

YES

YES

NO

NO

CHECK

R, G, B CATHODE

VOLTAGE?

TROUBLE IN
R331~R333,
L311~L313,
D307~D312

TROUBLE IN

CRT SOCKET

YES

NO

- 17 -

NO VIDEO

(POWER INDICATOR ON)

CHECK

POWER INDICATOR

GREEN or AMBER?

CHECK

D712 ANODE

(-157V)?

CHECK

G1VOLTAGE?

(-55~-15V)

TROUBLE IN

D712

TROUBLE IN

Q704

DPM MODE

(NO H and/or V SYNC)

AMBER

NO

GREEN

YES

NO

3. NO RASTER

CHECK

CDT HEAT

VOLTAGE? (6.3V)

TROUBLE IN

D941, Q942, Q941

YES

NO

TROUBLE IN

CDT

YES