LG 575N, 575C, CB575BN, CB575BC TROUBLESHOOTING GUIDE

TROUBLESHOOTING GUIDE

- 16 -

NO POWER

(POWER INDICATOR OFF)

TROUBLE IN
D901, D902, D903, D904

TROUBLE IN FUSE
(F901)

TROUBLE IN
IC901, IC902

TROUBLE IN
D930, D922, D923,
D924, D926

TROUBLE IN

IC903, Q920, Q922,

Q923, Q924, Q925, Q926

CHECK

FUSE OK?

CHECK

C907 VOLTAGE?

(AC120V: 170VDC,

AC220V: 310VDC)

NO

YES

YES

YES

YES

NO

NO

NO

CHECK

IC901 PIN 3

WAVEFORM

(SQUARE WAVE

COMES OUT?)

CHECK

D930, D922, D924,

D923, D926
VOLTAGE?

1. NO POWER

- 17 -

2. NO CHARACTER

NO CHARACTER

CHECK

IC302 PIN 7, 15, 18,

21(8V) ?

CHECK

IC302 PIN 6, 8, 10 ?

CHECK

IC302 PIN 16, 19, 22 ?

CHECK

IC303

PIN 1, 3, 5 ?

CHECK

IC303 PIN 6 (75V)

10 (15V) ?

TROUBLE IN
P302 15V LINE, IC304

TROUBLE IN
PC SIGNAL,
P301 SIGNAL CABLE

TROUBLE IN
IC302

TROUBLE IN
P302 15V LINE/75V LINE

TROUBLE IN IC303

NO

YES

NO

NO

YES

YES

YES

YES

NO

NO

CHECK

R, G, B CATHODE

VOLTAGE?

TROUBLE IN
R338~R341,
R344, R345, L302~L304,
D307~D310, D312, D313

TROUBLE IN

CDT SOCKET

YES

NO

- 18 -

NO VIDEO

(POWER INDICATOR ON)

CHECK

POWER INDICATOR

GREEN or ORANGE?

CHECK

D712 ANODE

(-120V)?

CHECK

G1VOLTAGE?

(-10 ~ -30V)

TROUBLE IN
D712

TROUBLE IN

D926, Q925 (6.3V)

TROUBLE IN
Q801~Q806, Q808

DPM MODE
(NO H and/or V SYNC)

ORANGE

NO

GREEN

YES

YES

NO

3. NO RASTER