TM 11-6625-1683-15
Probable trouble
Symptom
Correction
transformer T1: a square wave
ante, or short; use the multi-
with a frequency of approxi-
meter. Observe correct polarity.
mately 1 kHz and an amplitude of
Replace any defective capaci-
approximately 16 volts should be
tors.
obtained. If this is not observed:
c. Replace diodes (fig. 7-6).
open.
9. With correct square-wave output
observable at terminals 8 and 10
of power transformer T1, no de
voltage is obtained at output ter-
minal of filter FL3.
pulse, derived from the 4-kHz oscillation fre-
6-7. Checking Receiver-Transmitter Power
Converter 700
quency, is made available. Troubleshooting will be
aided by referring to the following chart.
The function of this power converter is to supply
voltages for testing. In addition, a synchronizing
Correction
Probable trouble
Symptom
With equipment operating from 115-
volt line, INPUT POWER switch
S1 at AC ON, and CIRCUIT
BREAKERS closed (on):
1. Take input voltage reading be-
1. Block 700 power converter not
1. No dc voltage readings between
tween GRD and TP6 on con-
functioning.
ground and any block 700 voltage
verter panel. If 6-volt reading
test jack.
is obtained, indicating satisfac-
tory input, replace converter.
For repairs on converter, refer
to TM 11-5840-298-35.
2. Replace block 700 power converter.
2. Block 700 power converter
2. Voltage readings obtainable at some,
For repair information, refer to
but not all, block 700 test jacks.
faulty.
TM 11-5840-298-35.
a. Check powerline fuses and
3. No ac power being furnished
3. No voltage readings at any block
switches.
700 test jack and no 6-volt
to circuits.
b. Make certain that all CIRCUIT
input indicated at TP6 on con-
BREAKERS are on (closed).
verter panel. AC ON indicator
light not on.
4. Repair internal power converter.
4. No voltage readings at any test jack
4. Internal power converter not
For repair information, refer to
in block 700 test area and no
functioning.
6-volt input indicated at TP6 on
converter panel. AC ON indicator
light is on.
range of the following specific dc voltages: +2,000,
6-8. Checking Control Indicator Power Con-
2,000, +35, +12, and 12. Troubleshooting will be
verter 2300
aided by referring to the following chart:
The function of this power converter is to supply a
Change 10 6-5
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