Power Supply Trouble Shooting Chart - Philips 107T7 Service Manual

17" CDT Color Monitor

7-9. Power Supply Trouble Shooting Chart

BEFORE CHECK SW.REG. PLEASE REFER TO THE POWER SUPPLY BLOCK DIAGRAM
POWER SUPPLY OUTPUT: (A) VARIABLE OUTPUT : 60V – 154.5V
BEAD SET
CHECK AC LINE
VOLT 120V OR 220V
NG
OK
CHECK LINE RECTIFIED &
SMOOTHED VOLT
NG
OK
CHECK START C.K.T
R939, R940, D912, ZD903
OK
CHECK T901 O/P
NG
OK
CHECK IC901
NG
OK
CHECK SENSE RESISTENCE
(DEPENDING EPENDING UPON H.SYNC FREQUENCY)
(B) CONSTANT OUTPUT : 6.3V, 14V,80V
CHECK F901, SW901
CHECK BRIDGE
RECTIFIED CIRCUIT
CHECK 56V, 14.5V
6.5V CIRCUIT OUTPUT
IC901 FAILURE
ABNORMAL VARIABLE OUTPUT
MAKE SURE THAT THE
VARIABLE OUTPUT IS NOT
SHORTED
NO
YES
CHECK THE 56V OUTPUT
NG
OK
CHECK Q911
NG
OK
IC101 PIN30 (ABOUT5V)
OK
32
107T7
CHECK IC101 PIN39,
40,41, B+ DRIVER
CHECK D925
Q911 FAILURE