NEC MultiSync 2A Service Manual page 32

SWITCHING REGULATOR CIRCUIT
13.
TURN OFF POWER SW ITCH. AFTER ONE M INUTE, D ISCONNECT CN- D6
AND CN- D7, THEN TURN ON POWER SW ITCH. MEASURE VOLTAGE
ACROSS C656 (+110V OUTPUT) AND ACROSS C660 (+24V OUTPUT)
RESPECT IVELY WITH A D IGITAL MULTIMETER (DMM).
APPROX. 110V MEASURED
ACROSS C656,
BUT OV ACROSS C660?
APPROX. 110V MEASURED ACROSS C656,
BUT APPROX. 24V NOT MEASURED ACROSS C660?
MORE THAN 18V MEASURED
ACROSS PINS 13 AND 16 OF
IC602?
VOLTAGE ACROSS IC602 P INS 13
AND 16 FLUCTUATING BETWEEN
APPROX. 1 OV AND 16V?
(DMM SHOULD READ APPROX 13V.)
VOLTAGE ACROSS IC602 P INS 13
AND 16 MEASURED BETWEEN 1V
AND 9V?
VOLTAGE ACROSS"+" AND
"-"TERMINALS
OF D601 APPROX. 170V?
FUSE F601 BLOWN?
R601 BURNT OUT?
YES
D652, L652
NO
NO
YES D651, PC601, ZD651
ZD602, IC651, IC602
NO
D651, D652, D604, D605
YES IC602, IC651, 0601, R619
R616,C654,C655,C662
C615,C620,C651,C652
C656,C658,C659,C660
NO
YES IC602, ZD602, C624
NO
YES
ZD601, R605
NO
YES
0601, IC602, D601, R601
R617, R622, R619
NO
YES
D606,CR601, R625,R626
C616, 0601, IC602, D606
R617, R622, R619
- 3 0 -
CHECK
C615, D604
CHECK
CHECK
CHECK
CHECK
CHECK
CHECK