Trouble Shooting Chart; No Raster, Crt Relative Circuit Problems - Acer AF715 Series Service Manual

6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS

CHECK MAIN PCB
CHECK MAIN PCB POWER SUPPLY
POWER SUPPLY 180V,16V,80V
60.5V, 14.5V, 80V
NG
OK
CHECK THE HIGE VOLTAGE OF
CHECK THE HIGE VOLTAGE
CRT ABOUT 25±0.3KV OR Q409
OF CRT ABOUT 25.5 ~ 26.5KV
DRAIN PIN VOLTAGE WAVE
NG
OK
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
NG
OK
CHECK SCREEN VOLTAGE
ABOUT 500V TO 800V
CHECK SCREEN VOLTAGE ABOUT
400V TO 700V
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

6.TROUBLE SHOOTING CHART

15
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
CHECK BRIGHTNESS CIRCUIT
Q705,Q706, RELATIVE CKT.
Q703, Q706, Q707 RELATIVE CKT.
REFER ITEM 6-2 "ABNORMAL
REFER ITEM 8-2
DISPLAY"
"ABNORMAL DISPLAY"