Table of Contents
Advertisement
5-44.
A defective part should be replaced (refer to the parts list in Section VI).
Test
points called out in the procedures are
identified
on the schematic
diagram
(figure
4-2).
5-45.
BIAS AND REFERENCE CIRCUIT. Proceed as follows:
a. Make an ohmmeter check to be certain that neither the positive nor
negative terminal
is
grounded
.
b. Turn front-panel VOLTAGE and CURRENT controls fully clockwise
.(maximum)
.
c. Tum-on power supply (no load
connec
ted).
d. Using the ac voltmeter, check voltage across secondary winding 5-6 of
transformer T2. If
voltage indication is not 23 :1:1. 5
vrms,
transformer T2
may
be
defective.
e
.
Using the differential voltmeter, proceed as instructed in table 5-3.
5-46
.
HIGH
OUTPUT VOLTAGE. Proceed as follows:
a. Turn front-panel CURRENT controls fully clockwise (maximum).
b
.
Turn
front-panel VOLTAGE controls to mid-position.
c
.
Turn-on power supply (no load connected).
d. Using
the ac voltmeter, check voltage across test points ACC and
45.
If
voltage
indication
is less than
1.
0 vac, CRl 7 or CRIB may be shorted.
e
.
Using the differential voltmeter, check voltage across test points 33 and
36. Ifvoltageisnot0.B:t:0.12vdc, checkT2, CR39 throughCR43, R50
,
andR51.
f.
Using
the differential voltmeter, proceed as instructed in table 5-4.
5-47.
LOW OUTPUT VOLTAGE
.
Proceed as follows:
a. Turn front-panel CURRENT controls fully clockwise
(maximum).
b
.
Disconnect anode or cathode of diode CRB.
c. Turn
-
on power supply (no load connected).
d
.
Turn front-panel VOLTAGE controls clockwise and observe the front-
panel voltmeter to
see
if
the 120vdc output can be obtained.
If
it can, the probable
cause
of
the low
output
voltage
is one or
more
of
the following:
5-11
Advertisement
Table of Contents
