Page 1
TROUBLE SHOOTING GUIDE
BASIC GUIDE
FOLLOW
NO POWER
PROCEDURE
FOLLOW
NO RASTER
PROCEDURE
FOLLOW
NO VERTICAL
DEFLECTION
PROCEDURE
FOLLOW
NO CHARACTER,
NO CONTRAST
PROCEDURE
FOLLOW OTHER
PROCEDURES
CHECK
SMPS SECONDARY
B+OUTPUT
CHECK
HORIZONTAL
OUTPUT
WAVEFORM
CHECK
VERTICAL OUTPUT
WAVEFORM
CHECK
VIDEO OUTPUT
WAVEFORM
NO
YES
YES
YES
YES
NO
NO
NO
- 14 -
Page 2
1. NO POWER
- 15 -
NO POWER
TROUBLE IN
F901, R901, D901, D902
TROUBLE IN
Q901, Q902, IC901,R904,
R905, R912, D906, D907
TROUBLE IN
D931~D933, D936, D937
OR THEIR CONNECTED
COMPONENTS
TROUBLE IN
IC931 CIRCUIT
TROUBLE IN
OTHER PRIMARY CIRCUIT
TROUBLE IN
D909, R916
CHECK C908
DC VOLTAGE?
CHECK
IC901
CHECK
T901
PIN 3 ?
CHECK
SMPS SECONDARY
DC VOLTAGE ?
CHECK
IC931 PIN 3
VOLTAGE (5V)?
NO
YES
YES
YES
YES
YES
NO NO
NO
NO
6.3V, 13V, 40V,
50V, 77V
DC=MORE THAN 130V
Page 3
- 16 -
2. NO CHARACTER
NO CHARACTER
CHECK
IC301 PIN 8 (8V)?
CHECK
IC301 PIN 2, 4, 6 ?
CHECK
IC301 PIN 11,
15, 18 ?
CHECK
R, G, B CATHODE
VOLTAGE ?
CHECK
VIDEO OUTPUT
Q341, Q351,
Q361 ?
TROUBLE IN
IC302 13V LINE
TROUBLE IN
PC SIGNAL,
C301, C302, C303
TROUBLE IN
IC301 CIRCUIT
TROUBLE IN
IC301 CIRCUIT
TROUBLE IN
VR347, VR357, VR367
VIDEO OUTPUT:
Q341, Q342, Q343, Q344,
Q351, Q352, Q353, Q354,
Q361, Q362, Q363, Q364
TROUBLE IN
CRT SOCKET
NO
YES
NO
NO
YES
YES
YES
YES
YES
YES
NORMAL=44~67V
NO
NO
CHECK
IC301 PIN 9
FOLLOW
NO CONTRAST
PROCEDURE
NO
1.2v
CHECK
IC301 PIN 19 ?
TROUBLE IN
CLAMP CIRCUIT
NO
Page 4
NO RASTER
(LED COLOR IS GREEN)
- 17 -
CHECK
CRT HEATER VOLTAGE?
(6.3
0.6V)
CHECK
CRT G1 (0
50V)?
CHECK
R, G, B CATHODE
OF CRT?
CHECK
FBT PIN 2
DC 65~150V?
CHECK
FBT PIN 1?
TROUBLE IN
HEATER VOLTAGE
SUPPLY CIRCUIT
( Q935, Q936 etc)
TROUBLE IN
G1 SUPPLY CIRCUIT
(D793, C785, Q722,
Q724, Q756, D794,
D797 etc)
FOLLOW
NO CHARACTER
PROCEDURE
FOLLOW
NO POWER
PROCEDURE
CHECK HORIZONTAL
DEFLECTION CIRCUIT
CHECK MUTE OR DPM
CIRCUIT
NO
NO
YES
YES
YES
YES
YES
NO
NO
NO
3. NO RASTER
~1.200VP-P
1.000
Page 5
- 18 -
NO ADJUSTED H-/V SIZE,
POSITION, S-PCC, TRAP.
CHECK
IC401 PIN 1, 2, 3,
38, 39, 40 ?
CHECK
IC701 PIN17, 18, 20, 21,
30, 32?
TROUBLE IN
IC401 (MICOM)
TROUBLE IN
IC701
TROUBLE IN
PWM CIRCUIT
NO
NO
YES
YES
4. TROUBLE IN H/V SIZE, H/V POSITION, S-PCC, TRAPEZOID
Page 6
NO V-DEFLECTION
(ONE HORIZONTAL LINE)
- 19 -
CHECK
IC601 PIN 3
(13V)?
CHECK
IC601 PIN 7
(40V)?
CHECK
IC701 PIN 12, 13?
TROUBLE IN
13V LINE, R601, C601
TROUBLE IN
40V LINE, R602, C604
TROUBLE IN
IC701
TROUBLE IN IC601,
V- DEFLECTION
CIRCUIT
NO
NO
YES
YES
YES
NO
5. NO VERTICAL DEFLECTION
Page 7
NO CONTRAST
- 20 -
CHECK
Q742?
CHECK
Q743?
CHECK
IC301 PIN 9 ?
TROUBLE IN Q742
TROUBLE IN Q743
TROUBLE IN
P902, P302,
VR850
TROUBLE IN IC301
NO
NO
YES
DC 0.8~5V
YES
YES
NO
6. NO CONTRAST
Page 8
CHECK
IC401 PIN 41, 42
(H/V SYNC)
CHECK
IC401 PIN 8, 9
WAVEFORM?
(4MHz)
CHECK
IC401
PIN 20, 21 ?
CHECK
B+LINE (6.3V, 13V) ?
CHECK PC,
(PC IS NOT GOING INTO
DPM OFF MODE)
Q451, Q452
TROUBLE IN
X401, IC401 (MICOM)
TROUBLE IN
IC401 (MICOM)
TROUBLE IN
B+LINE
TROUBLE IN PC
OFF MODE FAILURE
NO H/V SYNC SIGNAL
INPUT H/V SYNC
(NO OFF MODE)
NO
NO
NO
7. TROUBLE IN DPM
- 21 -
YES
YES
YES
Page 9
CHECK
Q941?
CHECK
Q941 COLLECTOR
VOLTAGE?
CHECK
P903?
CHECK
RL901?
TROUBLE IN
Q941, IC401
TROUBLE IN
Q941, RL901
TROUBLE IN
P903
TROUBLE IN
RL901
TROUBLE IN
TH901,
DEGAUSSING COIL
NO DEGAUSSING
NO
NO
NO
NO
8. NO DEGAUSSING
- 22 -
YES
YES
YES
YES
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