LG N2200P, NB230A-UA TROUBLESHOOTING GUIDE

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TROUBLESHOOTING GUIDE

1. NO POWER

NO POWER

(POWER INDICATOR OFF)

TROUBLE IN
D901

TROUBLE IN
FUSE (F901)

TROUBLE IN
IC902

CHECK

FUSE OK?

CHECK

C905 (+) VOLTAGE?

(400VDC AT INPUT
VOLTAGE 220VAC)

NO

YES

YES

NO

CHECK

Q901 DRAIN

WAVEFORM (SQUARE

WAVE COMES OUT?)

YES

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2. NO CHARACTER

CHECK

IC301 PIN 30 (12V),

PIN 2 (5V)?

CHECK

IC301 PIN 1, 3, 6 ?

CHECK

IC301 PIN 25, 27, 29 ?

TROUBLE IN
P301,
5V, 12V LINE

TROUBLE IN
PC SIGNAL,
SIGNAL CABLE, IC2231

TROUBLE IN

IC301

TROUBLE IN
CDT SOCKET

NO

YES

NO

NO

YES

YES

CHECK

R, G, B CATHODE

VOLTAGE?

TROUBLE IN

IC303

NO

YES

NO CHARACTER

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3. NO RASTER

NO VIDEO

(POWER INDICATOR

GREEN or ORANGE)

CHECK

POWER INDICATOR

GREEN or ORANGE ?

CHECK

SCREEN CONTROL

KNOB OF FBT

CHECK

VOLTAGE AT

D960 CATHODE (90V)

D962 CATHODE (210V)

D951 CATHODE (28V)
D957 CATHODE (80V)

D959 CATHODE (-15V)

D958 CATHODE (15V)

IC952 OUT (12V)

?

CHECK

IC271(MICOM) PIN 5

(5V), IC201 PIN 16

(12V)?

ROTATE SCREEN
CONTROL KNOB TO
CLOCKWISE

TROUBLE IN
IC271 (MICOM),
IC201 (T/BASE), TDA4856

TROUBLE IN
SECONDARY CIRCUIT
OF T901, T902

TROUBLE IN PRIMARY
CIRCUIT OF T901, T902

TROUBLE IN
D-SUB & 5-BNC
SIGNAL CABLE

ORANGE

MIN.
(Counter-clockwise)

GREEN

OK

YES

NO

YES

NO