12
6.TROUBLE SHOOTING CHART
6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
REFER ITEM S.M.P.S.
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
CATHODE ABOUT 60V TO 70V
CHECK SCREEN VOLTAGE ABOUT
LESS THAN 300V
CHECK FBT
CHECK MAIN PCB POWER SUPPLY
CHECK FAILSAFE CKT IC401
70V, 15V, 80V
Q909, Q910
CHECK CRT'S HEATER RELATIVE
CIRCUIT Q907, Q908
Q703, Q704, Q705 RELATIVE CKT.
PIN 25 RELATIVE CKT.
400V TO 600V
REFER ITEM 6-2
OF CRT ABOUT 23.5 ~ 25.5KV