TROUBLESHOOTING GUIDE
- 19 -
1. NO POWER
NO POWER
(POWER INDICATOR OFF)
TROUBLE IN
D901
TROUBLE IN
FUSE (F901)
TROUBLE IN
IC901 or Q902
TROUBLE IN
D923, D922, D931,
D924, D925, D927
TROUBLE IN
IC903
CHECK
FUSE OK?
CHECK
C912 (+) VOLTAGE?
(310VDC AT INPUT
VOLTAGE 110VAC)
NO
YES
YES
YES
NO
NO
NO
CHECK
Q902 DRAIN
WAVEFORM (SQUARE
WAVE COMES OUT?)
CHECK
D923, D922, D931,
D924, D925, D927
VOLTAGE?
YES
- 20 -
2. NO CHARACTER
CHECK
IC302 PIN 3, 8,12 (12V),
PIN 17 (5V)?
CHECK
IC302 PIN 2, 6,11 ?
CHECK
IC302 PIN 29, 32, 35 ?
TROUBLE IN
P302,
5V, 12V LINE
TROUBLE IN
PC SIGNAL,
SIGNAL CABLE, IC2001
TROUBLE IN
IC302
TROUBLE IN
CDT SOCKET
NO
YES
NO
NO
YES
YES
CHECK
R, G, B CATHODE
VOLTAGE?
TROUBLE IN
IC303
NO
YES
NO CHARACTER
- 21 -
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
D924 CATHODE (195V)
D925 CATHODE (80V)
IC911 OUT (12V)
IC960 CATHODE
(6.3V)?
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
- 22 -
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
- 23 -
5. TROUBLE IN DPM
CHECK
IC271 (MICOM)
PIN 42, 1 (H/V INPUT)
SIGNAL?
CHECK
IC271 PIN 6, 7
WAVEFORM?
CHECK
IC271 PIN 17
(5V, HIGH)?
CHECK
IC905 PIN 7
(15V) ?
CHECK PC,
(PC IS NOT GOING INTO
DPM MODE)
TROUBLE IN
X201, IC271
TROUBLE IN
IC271
TROUBLE IN
Q903, IC913, D914
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
R938
NO
YES
STAND-BY/SUSPEND/
OFF MODE FAILURE
- 24 -
6. NO DEGAUSSING
CHECK
IC271 PIN 22
(5V)?
CHECK
Q271 COLLECTOR
VOLTAGE
(0.5V)?
CHECK
P903, P904?
CHECK
RL901?
TROUBLE IN
IC271 (MICOM)
TROUBLE IN
Q271
TROUBLE IN
P903, P904
TROUBLE IN
RL901
TROUBLE IN
TH901,
DEGAUSSING COIL
NO DEGAUSSING
( BUTTON MUST BE PRESSED.)
NO
NO
NO
NO
YES
YES
YES
YES
- 25 -
7. NO TILT (ROTATION)
TROUBLE IN P613,
TILT COIL CONNECTOR,
TILT COIL
NO TILT (ROTATION)
TROUBLE IN
IC911, D922
TROUBLE IN
D923, IC613
CHECK
IC612 PIN 12 VOLTAGE
(5V) ?
NO
YES
YES
CHECK
IC612 PIN 4
(-12V) ?
NO
TROUBLE IN
IC271 (MICOM), IC704
IC612
YES
CHECK
IC612 PIN 3 ?
NO
- 26 -
8. TROUBLE IN OSD
CHECK
IC301 PIN 5
(NEGATIVE H-PULSE
COMES IN ?)
CHECK
IC301 PIN 10
(NEGATIVE V-PULSE
COMES IN?)
CHECK
IC301 PIN 13, 14, 15
(IS THERE ANY SIGNAL
WHEN OPERATING FRONT
CONTROL ?)
NO OSD
TROUBLE IN
IC302
TROUBLE IN
Q301, P302
TROUBLE IN
Q302, P302
TROUBLE IN
IC301, IC271
YES
YES
YES
NO
NO
NO
CHECK
IC301 PIN 4, 9
(5V) ?
TROUBLE IN
P302, D927
NO
YES
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