Power Supply Trouble Shooting Chart - ViewSonic E90fB-4 Service Manual

BEFORE CHECK SW.REG. PLEASE REFER TO THE POWER SUPPLY BLOCK DIAGRAM
POWER SUPPLY OUTPUT: (A)
BEAD SET
CHECK AC LINE
VOLT 120V OR 220V
NG
OK
CHECK LINE RECTIFIED
& SMOOTHED VOLT
NG
OK
CHECK START C.K.T
R936
OK
CHECK T901 O/P
NG
OK
CHECK IC901
NG
OK
CHECK SENSE RESISTENCE
ViewSonic Corporation

6-9 POWER SUPPLY TROUBLE SHOOTING CHART

VARIABLE OUTPUT : 60V
(B) CONSTANT OUTPUT : 6.3V, 14V,80V，200.V，－12V
CHECK F901, SW901
CHECK BRIDGE
RECTIFIED
CHECK 56V, 12V
6.5V CIRCUIT OUTPUT
IC901 FAILURE
23
ABNORMAL VARIABLE OUTPUT
MAKE SURE THAT
THE VARIABLE
OUTPUT IS NOT SHORTED
CHECK IC101
NO
PIN39,40,41, B+
DRIVER
YES
CHECK THE 56V OUTPUT
NG
CHECK D925
OK
CHECK Q911
NG
Q911 FAILURE
OK
IC101 PIN30(ABOUT5V)
OK
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E90fB-4