Fujitsu 154V, MCM1514V, C551, D556Q manual Power Supply Trouble Shooting Chart

6-9 POWER SUPPLY TROUBLE SHOOTING CHART

BEFORE CHECK SW.REG. PLEASE REFER TO THE POWER SUPPLY BLOCK DIAGRAM

POWER SUPPLY OUTPUT: (A) VARIABLE OUTPUT : 90V - 160V

(DEPENDING UPON H.SYNC FREQUENCY)

(B) CONSTANT OUTPUT : 6.3V, 15V, -12V, 75V

BEAD SET

CHECK AC LINE VOLT 120V OR 220V

ABNORMAL VARIABLE OUTPUT

MAKE SURE THAT

THE VARIABLE

OUTPUT IS NOT SHORTED

NG

OK

CHECK LINE

RECTIFIED & SMOOTHED VOLT

CHECK F901,SW901NO

YES

CHECK IC401

H-OSC SEE ITEM 1

CHECK 75V LINE

NG

OK

CHECK START C.K.T D909,Q904,R922

OK

NG

CHECK BRIDGE OK

RECTIFIED CIRCUIT

CHECK Q911

NG

OK

CHECK D919

Q911 FAILURE

CHEC (IT S

CHECK T901 O/P

NG

OK

CHECK IC901

NG

OK

OK

CHECK 75V,- 12V,
		CHECK Q901
15V,	6.3V CIRCUIT
NG

IC901 FAILURE

CHECK Q901