HP 4328A - Power Supply Troubleshooting

Model 4328A
TABLE 8-9
POWER SUPPLY TROUBLESHOOTING
>(
~22V
MEASURE ±13V
SUPPLY
MOTHER BOARD
(WHT/RED, WHT)
< 12V
MEASURE VOLTAGE
ACROSS C301
12V TO 14V CHECK
-+--REGULATION- CR305,
BAD R302
MEASURE VOLTAGE
AT Q302 COLLECTOR
> 14V
MEASURE VOLTAGE
ACROSS CR305 -
<(
CHECK FUSE,
TRANSFORMER,
C301, CR301 -
OV CR304
CHECK
OK-Q301, Q302,
Q303
REPLACE
BAD-FAULTY
COMPONEN
IF READING IS SAME,
CHECK AND REPLACE
FAULTY Q302
IF SLIGHTLY DIFFEREN'I
BUT HIGH, CHECK
CR305, R302, R303, R304