TM 1-1520-238-T-4
6–135
6–62.
OIL HOT NOSE GRBX 1 INDICATOR – IS LIGHTED WHEN HOD DISPLAYS NORMAL
6–62
NGB 1 OIL TEMPERATURE (cont)
7. Check for 10 VDC between P673–87 and
P673–86.
Is voltage present?
YES
Refer to TM 9-1230-476-20-2 to
troubleshoot multiplex
subsystem.
NO
Go to step 8.
8. Check for open between P61–H and P61–J.
Does open exist?
YES
Replace NGB 1 oil temperature
probe (TM 1-1520-238-23).
NO
Go to step 11.
9. Check for 28 VDC at J61–F.
Is voltage present?
YES
Repair open wire between
J61–G and GS574–A.
Go to paragraph 6–13.
NO
Go to step 10.
10. Check for open between:
P61–F and P439–A10,
P439–A14 and P463–c.
(A402):
J21–A10 and J21–A14.
Does open exist?
YES
Repair open wire.
Go to paragraph 6–13.
NO
Refer to TM 1-1520-238-T-6 to
troubleshoot circuit protection
system (dc emergency bus –
pilot station)
11. Check for short between P61–H and P61–J.
Does short exist?
YES
Replace NGB 1 oil temperature
probe (TM 1-1520-238-23).
NO
Repair shorted wire between:
J61–H and P403–B1,
J61–J and P403–B2,
J403–B2 and P673–86,
J403–B1 and P673–87.
Go to paragraph 6–13.
END OF TASK
