Power Supply Trouble Shooting Chart - Tatung VM9G5DA S995T Service Manual

BEFORE CHECK SW.REG. PLEASE REFER TO THE POWER SUPPLY BLOCK DIAGRAM
POWER SUPPLY OUTPUT: (A) VARIABLE OUTPUT : 60V - 186V (DEPENDING UPON H.SYNC
BEAD SET
CHECK AC LINE
VOLT 120V OR 220V
NG
OK
CHECK LINE
RECTIFIED &
SMOOTHED VOLT
NG
OK
CHECK MAIN POWER
CKT.
NG
OK
CHECK T901 O/P
NG
OK
CHECK MCU H-SYNC
V-SYNC IC901
OK
CHECK Q901

6-12 POWER SUPPLY TROUBLE SHOOTING CHART

FREQUENCY)
(B) CONSTANT OUTPUT : 7V, 20V, 29V, 54V, 80V
ABNORMAL VARIABLE OUTPUT
CHECK F901,SW901
CHECK D901, D902,
D903, D904
CHECK POWER
SAVING CKT(OFF
MODE)
CHECK 80V,55V,14.5V,
6.3V CIRCUIT
IC901 FAILURE
MAKE SURE THAT
THE VARIABLE
OUTPUT IS NOT SHORTED
YES
NO
CHECK THE C934
VOLTAGE 55V
NG
OK
CHECK Q911
NG
OK
CHECK Q912, Q914, Q915
CHECK IC401
PIN 4, 5, 6, B+
DEIVER
CHECK D919
Q911 FAILURE