TM 1-1520-238-T-4
4–98
4–19.
ENGINE 1 – DOES NOT ACCELERATE TO OR REMAIN BETWEEN 23% AND 25% NG
4–19
IN IGN OVRD (cont)
7. Have assistant check engine 1 starter regulator
valve operation while cycling ENG START NO 1
switch between OFF and IGN OVRD.
Does valve operate?
YES
Replace engine 1 air turbine
starter (TM 1-1520-238-23).
NO
Replace engine 1 starter
regulator valve
(TM 1-1520-238-23).
8. Check for open between:
J21–24 and P977–A17,
P977–A13 and P439–A16 ,
(A402)J21–A16 and (A402)TB2–8–E,
(A402)TB2–8–A and (A402)J21–A14.
Does open exist?
YES
Repair open wire.
Go to paragraph 4–12.
NO
Go to step 9.
9. Check for 28 VDC at (A76)J1–X.
Is voltage present?
YES
Go to step 10.
NO
Refer to TM 1-1520-238-T-6 to
troubleshoot circuit protection
system (dc emergency bus –
pilot station).
10. Check for open between:
P463–c and P439–A14 ,
P173–K and P977–B2.
Does open exist?
YES
Repair open wire.
Go to paragraph 4–12.
NO
Replace pilot power quadrant
(TM 1-1520-238-23).
11. Check for 28 VDC at (A402)TB2–8–A.
Is voltage present?
YES
Go to step 13.
NO
Go to step 12.
12. Check for open between:
P463–c and P439–A14.
(A402):
J21–A14 and TB2–8–A.
Does open exist?
YES
Repair open wire.
Go to paragraph 4–12.
NO
Refer to TM 1-1520-238-T-6 to
troubleshoot circuit protection
system (dc emergency bus –
pilot station).
13. Check for open between P977–A13 and
(A402)TB2–8–E.
Does open exist?
YES
Repair open wire.
Go to paragraph 4–12.
NO
Replace start mode relay panel
(TM 1-1520-238-23).
END OF TASK
