Failure of the VOR/ADF/DME RMI

TASK 34-57-00-810-803-A
Failure of the VOR/ADF/DME RMI

1. Possible Causes

RMI-VOR/ADF/DME [21FN]
wiring from the circuit breaker (12FN) to the VOR/ADF/DME RMI (21FN)
wiring of the ground signal at the VOR/ADF/DME RMI (21FN)
C/B-NAV/VOR/DME/RMI or C/B [12FN]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-14-00-740-001	Interface Test of the IR
ASM 345701
AMM 34-57-22-000-002	Removal of the VOR/ADF/DME RMI
AMM 34-57-22-400-002	Installation of the VOR/ADF/DME RMI

3. Fault Confirmation
Subtask 34-57-00-865-055-A ** ON A/C NOT FOR ALL

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	NAV/VOR/DME/RMI	12FN	F13

Subtask 34-57-00-740-054-A ** ON A/C NOT FOR ALL

B. Test
(1) Do the Interface test of the IR (but read only the heading value on the RMI) AMM 34-14-00-740-001.
(a) If the circuit breaker (12FN) is open, refer to Para. 4.B. of this trouble shooting procedure.

4. Fault Isolation
Subtask 34-57-00-810-054-B ** ON A/C NOT FOR ALL

A. If the circuit breaker (12FN) is closed and if the HDG flag comes into view on the RMI:

do a check for 115VAC at the VOR/ADF/DME RMI (21FN).

(1) If there is 115VAC:

replace the RMI-VOR/ADF/DME [21FN] AMM 34-57-22-000-002 and AMM 34-57-22-400-002.

(2) If there is no 115VAC:

do a check of the wiring from the circuit breaker (12FN) to the VOR/ADF/DME RMI (21FN).
do a check of the wiring of the ground signal at the VOR/ADF/DME RMI (21FN) : pin A/55.
ASM 345701.

(a) If there is no continuity:

repair the above wiring.

(b) If there is continuity:

replace the C/B-NAV/VOR/DME/RMI or C/B [12FN] .

Subtask 34-57-00-810-055-B ** ON A/C NOT FOR ALL

B. If the circuit breaker (12FN) is open:

close the circuit breaker.

(1) If the circuit breaker (12FN) trips:

remove the RMI-VOR/ADF/DME [21FN] AMM 34-57-22-000-002.
close the circuit breaker (12FN)

(a) If the circuit breaker stays closed:

replace the VOR/ADF/DME RMI (21FN) AMM 34-57-22-400-002

(b) If the circuit breaker trips again:

do a check for a short to ground between the circuit breaker (12FN) and the VOR/ADF/DME RMI (21FN) ASM 345701.

1 If there is a short to ground:

repair the above wiring.

2 If there is no short to ground:

replace the C/B-NAV/VOR/DME/RMI or C/B [12FN] .

3 Install the VOR/ADF/DME RMI (21FN) AMM 34-57-22-400-002

Subtask 34-57-00-740-055-A ** ON A/C NOT FOR ALL

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:33 UTC