15
6.TROUBLE SHOOTING CHART
6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
REFER ITEM S.M.P.S.
CHECK CRT'S HEATER RELATIVE
CIRCUIT
BRIGHTNESS SET TO MAX.
THEN CHECK CRT G1 VOLTAGE
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
CHECK THE HIGE VOLTAGE
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
CHECK VOLTAGE OF THE CRT
CHECK BRIGHTNESS CIRCUIT
OK
CHECK POWER SAVING CIRCUIT,
"ABNORMAL DISPLAY"
H-SYNC, V-SYNC SIGNAL
REFER ITEM 8-2
CATHODE ABOUT 60V TO 70V
CHECK SCREEN VOLTAGE ABOUT
400V TO 700V
OF CRT ABOUT 25.5 ~ 26.5KV
LESS THAN 300V
CHECK FBT
CHECK MAIN PCB POWER SUPPLY
60.5V, 14.5V, 80V
CHECK FAILSAFE CKT IC401
PIN 2 RELATIVE CKT.
Q703, Q706, Q707 RELATIVE CKT.
CHECK MAIN PCB
POWER SUPPLY 180V,16V,80V
CHECK THE HIGE VOLTAGE OF
CRT ABOUT 25
±
0.3KV OR Q409
DRAIN PIN VOLTAGE WAVE
CHECK SCREEN VOLTAGE
ABOUT 500V TO 800V
CHECK BRIGHTNESS CIRCUIT
Q705,Q706, RELATIVE CKT.
REFER ITEM 6-2 “ABNORMAL
DISPLAY”
