6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
REFER ITEM S.M.P.S.
BRIGHTNESS SET TO MAX.
CHECK CRT G1 VOLTAGE
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
CHECK THE HIGE
CHECK THE VOLTAGE OF
HEATER ABOUT 6.3V
CHECK VOLTAGE OF THE
CHECK BRIGHTNESS
OK
CHECK POWER SAVING
"ABNORMAL
H-SYNC,
V-SYNC
CHECK SCREEN VOLTAGE
LESS THAN 300V
CHECK FBT
CHECK MAIN PCB POWER
CHECK FAILSAFE CKT
Q909,
CHECK CRT'S HEATER
CIRCUIT Q907,
Q705 RELATIVE CKT.
PIN 25 RELATIVE CKT.
OF CRT ABOUT 25.5 ~
400V TO 600V
REFER ITEM 6-2
53V, 14V, 80V
CATHODE ABOUT 65V TO
CHECK MAIN PCB POWER
SUPPLY 57.5V,14V,80V
CHECK THE HIGE VOLTAGE OF
CRT ABOUT 24.5~26.5KV
CHECK BRIGHTNESS CIRCUIT
Q705 RELATIVE CKT.
6. Trouble Shooting Flow Chart
ViewSonic Corporation
Confidential – Do Not Copy
E70f-5_E70fB-5_E70fSB-5
16