TM 1-1520-238-T-6
9–538
9–258. MUX R PYL OUTBD CIRCUIT BREAKER (CB6) – DOES NOT STAY CLOSED
9–258
OR CONTINUITY DOES NOT EXIST BETWEEN (A77): J4-A AND J2-10
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 9-1230-476-20-2
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 MUX R PYL OUTBD circuit breaker
(CB6) stay closed?
YES
Go to step 4.
NO
Go to step 2.
2. Set BATT/EXT PWR switch to OFF. Check for
short between (A77)J2-10 and ground.
Does short exist?
YES
Go to step 3.
NO
Refer to TM 9-1230-476-20-2 to
troubleshoot multiplex
subsystem.
3. Detach wire at CB6-2. Check for short between
(A77)J2-10 and ground.
Does short exist?
YES
Repair shorted wire between
CB6-2 and (A77)J2-10.
Go to paragraph 9–249.
NO
Replace MUX R PYL OUTBD
circuit breaker (CB6)
(TM 1-1520-238-23).
4. Open CB6. Set BATT/EXT PWR switch to OFF.
Check for open between CB6-2 and (A77)J2-10.
Does open exist?
YES
Repair open wire.
Go to paragraph 9–249.
NO
Go to step 5.
5. Check for open between J4-A and CB15-1.
Does open exist?
YES
Repair open wire. Go to
paragraph 9–249.
NO
Go to step 6.
6. Check for open between CB15-1 and CB2-1.
Does open exist?
YES
Repair open wire. Go to
paragraph 9–249.
NO
Go to step 7.
7. Check for open between CB2-1 and CB1-1.
Does open exist?
YES
Replace bus bar between CB2
and CB1, and check for foreign
material (TM 1-1520-238-23).
NO
Go to step 8.
8. Check for open between CB1-1 and CB5-1.
Does open exist?
YES
Repair open wire. Go to
paragraph 9–249.
NO
Go to step 9.
