ViewSonic VX1933W Service Manual page 82

6.5 Backlight can't be turned on
Is there high-level voltage
on pin8 of IC501?
Are connected rightly
CN501, CN502?
Is there instantaneously pulse
wave on pin14, pin11 of IC501
at the moment of restart?
Is T501 ok?
Check feedback circuit
ViewSonic Corporation
No raster?
Yes
LED Blue?
Yes
Backlight can't
be turned on.
Yes
Is there 14Vdc
voltage on pin9
of IC501?
Yes
Yes
Yes
Yes
Yes
No
Check power
No
Is Ok R503?
No
No
Is Ok IC501?
No
79 CONFIDENTIAL – DO NOT COPY
Yes
No
R503 open
Connecting the
output connector
Yes
U501 fail
No
IC501 fail
T501 fail
END
Check I/F
VX2433wm-1
VX2433wm-CN