ViewSonic VX715 - Page 32

ViewSonic Corporation
32
6.6 No Backlight
Check C201(+) =12V
N
G
OK
Change F902
Check D201/Q209/Q210/D202/Q211/Q212
Check ON/OFF signal
Check Interface board
N
G
OK
Check U201 pin9=12V voltage of C905(+)
N
G
OK
Change Q201 or Q202
Check the pin1 of U201 have saw tooth wave
N
G
OK
Change U201
Check D201(-), D202(-) have the output of square wave at short time.
N
G
OK
CheckQ205/Q207/Q203/Q201 or
/Q206/Q208/Q204/D202
Check the resonant wave of pin2 & pin5 for PT201/ PT202
N
G
Check the output of PT201/PT202
Check Q209/Q210/C213 or Q211/C212/C214
Check connecter & lamp
OK
N
G
Change PT201/PT202
OK