5.3 MALFUNCTION
OF
SOURCE
A,
B,
or
C
The
first
step in
trouble
shooting any Source is
to
make sure the B + regulated voltages
measured on
capacitors
"A"
C104,
"B"
C204,
"C"
C304 fall
within
12.4 VDC and 13.2 voe
and are very stable. If these voltages are present, the voltages across zener diodes
"A"
VR103,
"B"
VR203,
"C"
VR302, should fall between 5.0 and 5.8V. If these voltages
do
not fall
within
the tolerances specified,
check
for
defective
components as follows:
"A"
C101-C104, CR101, 0101, VR101, *VR102, VR103,
U101
"B"
C201-C204, CR201, 0201, VR201, *VR202, VR203,
U201
"C"
C301-C304, CR301, 0301, VR301, VR302, *VR303,
U301
*Note:
"A"
VR102,
"B"
VR202,
"C"
VR303, are the main reference voltage
of
the cor-
responding Source;
their
voltages
must
fall between 6.26V and 6.52VDC.
5.3.1
NO
DC
OUTPUT
If FAULT
display
is
off
and VOLTAGE control is clockwise,
check
blown secondary
protection on
"A"
F101,
"B"
F201,
"C"
F302;
if
fuse
blows
after
replacement, pro-
bable cause is shorted
transistor
as follows:
"A"
0102, 0103,
0104
"B"
0202, 0203,
0204
"C"
0303, 0304, 0306, 0307,
0308
If fuse is
not
blown, check
for
shorted feedback
capacitor
"A"
C111,
"B"
C211,
"C"
312.
If FAULT
display
is on, set the CURRENT and OV
controls
clockwise;
if
ammeter
shows
current reading, check
for
shorted component as
follows:
"A"
C401,
CR1101
CR211,
CR401
"B"
C402, CR210, CR211, CR402
"C"
C403, CR309, CR403,
0305
-11 -
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