TM 1-1520-238-T-6
9–543
9–262. 28 VDC – IS NOT PRESENT AT P769-A AND P769-J
9–262
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
One person to assist
References:
TM 1-1520-238-23
Equipment Conditions:
Ref
Condition
Paragraph 9–148
All dc essential bus 3 pilot
station circuit breakers
open
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 ELEC PWR panel, set BATT/EXT PWR
switch to EXT PWR. Check for 28 VDC at
P769-A.
Is voltage present?
YES
Go to step 15.
NO
Go to step 2.
2. Check for 28 VDC at (A402)J32-J.
Is voltage present?
YES
Repair open wire between
P461-J and P769-A.
Go to paragraph 9–249.
NO
Go to step 3.
3. Set BATT/EXT PWR switch to OFF. Check for
short between P461-J and ground.
Does short exist?
YES
Go to step 4.
NO
Go to paragraph 9–23 to
troubleshoot dc electrical power
generation.
4. Check for short between (A77)J4-A and ground.
Does short exist?
YES
Go to step 5.
NO
Repair shorted wire between
P461-J and P769-A.
Go to paragraph 9–249.
5. Detach wire at CB15-1. Check for short between
(A77)J4-A and ground.
Does short exist?
YES
Repair shorted wire between
CB15-1 and (A77)J4-A.
Go to paragraph 9–249.
NO
Go to step 6.
6. Check for short between CB15-1 and ground.
Does short exist?
YES
Replace MUX CPG circuit
breaker (CB15)
(TM 1-1520-238-23).
NO
Go to step 7.
7. Attach CB15 wire and detach wire at CB2-1.
Check for short between (A77)J4-A and ground.
Does short exist?
YES
Repair shorted wire between
CB2-1 and CB15-1.
Go to paragraph 9–249.
NO
Go to step 8.
