Page 1
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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
Page 2
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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
Page 3
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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
Page 4
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4. NO VERTICAL DEFLECTION
NO V-DEFLECTION
(ONE HORIZONTAL LINE)
CHECK
IC601 PIN 2 (15V) ?
CHECK
IC601 PIN 4
(-12V)?
TROUBLE IN
T901 PIN 18
TROUBLE IN
T901 PIN 17
TROUBLE IN
IC601, VERTICAL
OUTPUT CIRCUIT
NO
NO
YES
YES
CHECK
IC201 PIN 12
(SAWTOOTH WAVE)?
TROUBLE IN
IC201
NO
YES
Page 5
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5. TROUBLE IN DPM
CHECK
IC271 (MICOM)
PIN 42, 1 (H/V INPUT)
SIGNAL?
CHECK
IC271 PIN 6, 7
WAVEFORM?
CHECK
IC271 PIN 4
(5V, HIGH)?
CHECK
IC951 PIN 7
(15V) ?
CHECK PC,
(PC IS NOT GOING INTO
DPM MODE)
TROUBLE IN
X201, IC271
TROUBLE IN
IC271
TROUBLE IN
IC905, IC953, Q952
TROUBLE IN
T901 or PC
NO H / V SYNC SIGNAL
INPUT H/V SYNC
NO
NO
NO
DPMS TABLE
Mode
Item
NORMAL
STAND-BY
SUSPEND
OFF
H / V SYNC
ON / ON
OFF / ON
ON / OFF
OFF / OFF
LED
GREEN
ORANGE
ORANGE
ORANGE
VIDEO
NORMAL
OFF(0V)
OFF(0V)
OFF(0V)
YES
YES
CHECK
B+ LINE
(12V, 15V, 80V,
5V) ?
TROUBLE IN
R955
NO
YES
STAND-BY/SUSPEND/
OFF MODE FAILURE
Page 6
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6. NO DEGAUSSING
CHECK
IC271 PIN 17
(5V)?
CHECK
Q902 COLLECTOR
VOLTAGE
(0.5V)?
CHECK
P901?
CHECK
RL901?
TROUBLE IN
IC271 (MICOM)
TROUBLE IN
Q271
TROUBLE IN
P901
TROUBLE IN
RL901
TROUBLE IN
TH901,
DEGAUSSING COIL
NO DEGAUSSING
( BUTTON MUST BE PRESSED.)
NO
NO
NO
NO
YES
YES
YES
YES
Page 7
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7. NO TILT (ROTATION)
TROUBLE IN P661,
TILT COIL CONNECTOR,
TILT COIL
NO TILT (ROTATION)
TROUBLE IN
D958
TROUBLE IN
D959
CHECK
IC651 PIN 8 VOLTAGE
(15V) ?
NO
YES
YES
CHECK
IC651 PIN 4
(-15V) ?
NO
TROUBLE IN
IC271 (MICOM), IC691
IC651
YES
CHECK
IC651 PIN 3 ?
NO
Page 8
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8. TROUBLE IN OSD
CHECK
IC302 PIN 5
(NEGATIVE H-PULSE
COMES IN ?)
CHECK
IC302 PIN 14
(NEGATIVE V-PULSE
COMES IN?)
CHECK
IC302 PIN 17, 18, 19
(IS THERE ANY SIGNAL
WHEN OPERATING FRONT
CONTROL ?)
NO OSD
TROUBLE IN
IC301
TROUBLE IN
Q301, P303
TROUBLE IN
Q384, P303
TROUBLE IN
IC302, IC271
YES
YES
YES
NO
NO
NO
CHECK
IC302 PIN 4, 13
(5V) ?
TROUBLE IN
P303, D909
NO
YES
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