6.TROUBLE SHOOTING CHART
1.ABNORMAL POWER SUPPLY
90V,12V
CHECK MAIN PC BOARD
NG
OK
CHECK THE HIGE VOLTAGE OF CRT ABOUT 23.5 ~ 25.5KV
CHECK POWER SAVING CIRCUIT Q909,Q910
NG
OK
CHECK THE VOLTAGE OF CRT HEATER ABOUT 6.3V
NG
CHECK FAILSAFE CKT Q402,Q403
RELATIVE CKT.
CHECK CRT’S HEATER RELATIVE CIRCUIT Q907,Q908
OK
CHECK SCREEN VOLTAGE ABOUT 400V TO 600V RELATIVE CKT.
LESS THAN 300V
OK
BRIGHTNESS SET TO MAX. THEN CHECK CRT G1 VOLTAGE
NG
OK
CHECK VOLTAGE OF THE CRT CATHODE ABOUT 60V TO 70V
NG
CHECK FBT. D706,R723,C713
CHECK BRIGHTNESS CIRCUIT Q703,Q704,Q705 RELATIVE CKT.
REFER ITEM
“ABNORMAL DISPLAY”
