TM 1-1520-238-T-6
9–662
9–335. LT CAUT CIRCUIT BREAKER (CB21) – DOES NOT STAY CLOSED
9–335
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
References:
TM 1-1520-238-23
Equipment Conditions:
Ref
Condition
Paragraph 9–149
Pilot circuit breaker panel
accessing – completed
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. On pilot center circuit breaker panel, open LT
CAUT circuit breaker (CB21). Check for short
between (A76)J1-y and ground.
Does short exist?
YES
Go to paragraph 9–263 to
troubleshoot dc emergency bus
– pilot station.
NO
Go to step 2.
2. With wire ends (A326):
TB1-12-A and TB1-12-D detached, check for
short between (A326):
TB1-12-A and ground,
TB1-12-D and ground.
Does short exist?
YES
Go to step 3.
NO
Go to step 4.
3. With wire ends (A326):
TB1-12-A and TB1-12-D detached, check for
short between J164-A17 and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–333.
NO
Replace pilot master
caution/warning panel
(TM 1-1520-238-23).
4. With wire ends (A326):
TB1-12-B and TB1-12-C detached, check for
short between (A326):
TB1-12-B and ground,
TB1-12-C and ground.
Does short exist?
YES
Go to step 8.
NO
Go to step 5.
5. With wire end (A326)TB1-12-E detached, check
for short between (A326)TB1-12-E and ground.
Does short exist?
YES
Go to step 7.
NO
Go to step 6.
6. With wire end (A326)TB1-12-F detached, check
for short between P20-H and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–333.
NO
Replace tail rotor gearbox
temperature alarm
(TM 1-1520-238-23).
7. With wire end (A326)TB1-12-E detached, check
for short between P748-s and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–333.
NO
Replace multi-channel dimming
controller (TM 1-1520-238-23).
