TM 1-1520-238-T-6
9–580
9–287. RDR ALT CIRCUIT BREAKER (CB31) – DOES NOT STAY CLOSED
9–287
OR 28 VDC IS NOT PRESENT AT (A76): J1-f AND J1-g
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
TM 11-1520-238-23-2
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.
Does RDR ALT circuit breaker (CB31) stay
closed?
YES
Go to step 4.
NO
Go to step 2.
2. On pilot center circuit breaker panel, open RDR
ALT circuit breaker (CB31). Set BATT/EXT PWR
switch to OFF. Check for short between (A76):
J1-f and ground,
J1-g and ground.
Does short exist?
YES
Go to step 3.
NO
Refer to TM 11-1520-238-23-2
to troubleshoot radar altimeter
set.
3. Detach wire at CB31-2. Check for short between
(A76):
J1-f and ground,
J1-g and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–263.
NO
Replace RDR ALT circuit
breaker (CB31)
(TM 1-1520-238-23).
4. Set BATT/EXT PWR switch to OFF. Check for
open between:
CB31-2 and (A76)J1-f,
CB31-2 and (A76)J1-g.
Does open exist?
YES
Repair open wire.
Go to paragraph 9–263.
NO
Replace RDR ALT circuit
breaker (CB31)
(TM 1-1520-238-23).
END OF TASK
