Trouble Shooting Chart; Raster, Crt Relative Circuit Problems - Tatung VM9K9DA P990S Service Manual

6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
CHECK MAIN PCB POWER SUPPLY
60.5V, 14.5V, 80V
OK
CHECK THE HIGE VOLTAGE
OF CRT ABOUT 25.5 ~ 26.5KV
26.5~27.5K
V
OK
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
OK
CHECK SCREEN VOLTAGE ABOUT
400V TO 700V
OK
BRIGHTNESS SET TO MAX.
THEN CHECK CRT G1 VOLTAGE
OK
CHECK VOLTAGE OF THE CRT
CATHODE ABOUT 60V TO 70V

6.TROUBLE SHOOTING CHART

NG
NG
NG
LESS THAN 300V
NG
NG
CHECK POWER SAVING CIRCUIT,
H-SYNC, V-SYNC SIGNAL
OK
REFER ITEM S.M.P.S.
CHECK FAILSAFE CKT IC401
PIN 2 RELATIVE CKT.
CHECK CRT'S HEATER RELATIVE
CIRCUIT
CHECK FBT
CHECK BRIGHTNESS CIRCUIT
Q703, Q706, Q707 RELATIVE CKT.
REFER ITEM 8-2
"ABNORMAL DISPLAY"