![background image](http://html1.mh-extra.com/html/viewsonic/g90fb-4/g90fb-4_service-manual_1020357024.webp)
6-12. Power supply trouble shooting chart
Before check SW.REG.Please refer to the power supply block diagram power supply output
:
(A)
Variable output
: 60V
(B)
Constant output
: 6.3V, 12V,83V
,
180.V
,-
12V
BEAD SET
ABNORMAL VARIABLE OUTPUT
NG
OK
NG
OK
OK
NG
NG
OK
OK
OK
NG
OK
NG
YES
NO
CHECK BRIDGE
RECTIFIED
CHECK START C.K.T
CHECK IC101
CHECK D925
CHECK Q911
Q911 FAILURE
CHECK IC901
CHECK AC LINE
VOLT 120V OR 220V
CHECK F901, SW901
CHECK LINE RECTIFIED
& SMOOTHED VOLT
CHECK SENSE RESISTENCE
IC901 FAILURE
CHECK T901 O/P
MAKE SURE THAT
THE VARIABLE
OK
OUTPUT IS NOT SHORTED
R936
PIN39,40,41, B+
DRIVER
6.5V CIRCUIT OUTPUT
IC101 PIN30(ABOUT5V)
CHECK 56V, 12V
CHECK THE 56V OUTPUT
ViewSonic Corporation
Confidential - Do Not Copy
G90fB-4
21