Trouble Shooting Flow Chart - ViewSonic PerfectFlat E90fB-4 Service Manual

6. Trouble Shooting Flow Chart

6-1-1. NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
CHECK MAIN PCB POWER SUPPLY
200V, 14V, -12V,7V,80V
OK
CHECK THE HIGE VOLTAGE
OF CRT ABOUT 25.5~ 26.5KV
OK
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
OK
CHECK SCREEN VOLTAGE ABOUT
400V TO 600V
OK
BRIGHTNESS SET TO MAX. THEN
CHECK CRT G1 VOLTAGE
OK
CHECK VOLTAGE OF THE CRT
CATHODE ABOUT 56V TO 65V
ViewSonic Corporation
NG
NG
NG
LESS THAN 300V
NG
NG
CHECK POWER SAVING CIRCUIT,
H-SYNC, V-SYNC SIGNAL
Q907,Q935
REFER ITEM S.M.P.S.
CHECK IC101 PIN18 OUTPUT
.
CHECK CRT'S HEATER RELATIVE
CIRCUIT Q907, Q935
CHECK FBT
CHECK BRIGHTNESS CIRCUIT
Q705 RELATIVE CIRCUIT
REFER ITEM 6-2
"ABNORMAL
17
Confidential - Do Not Copy
OK
E90fB -4