Loss of the Tuning Data for the VHF 1 System

TASK 23-13-00-810-805-A
Loss of the Tuning Data for the VHF 1 System

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-12-00-740-001	BITE Test of the VHF System
AMM 23-12-33-000-001	Removal of the VHF Transceiver
AMM 23-12-33-400-001	Installation of the VHF Transceiver
ASM 231302
AMM 23-13-13-000-001	Removal of the Radio Management Panel (RMP)
AMM 23-13-13-400-001	Installation of the Radio Management Panel (RMP)

3. Fault Confirmation
Subtask 23-13-00-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	COM/RMP/1	2RG1	G10

Subtask 23-13-00-860-054-A

B. Job Set-Up
On the RMP 1 only, make sure that the ON/OFF switch is at ON.

Subtask 23-13-00-740-058-A

C. Test
(1) Do the BITE test of the VHF system AMM 23-12-00-740-001.

NOTE: Do this test for the VHF 1 only.

4. Fault Isolation
Subtask 23-13-00-810-054-B

A. If the test confirms the fault:

(1) If the fault continues:

Replace the RMP-COM/NAV FREQ SEL, 1 [1RG1] AMM 23-13-13-000-001 and AMM 23-13-13-400-001.

(2) If the fault continues:

Do a check and repair the wiring from VHF 1 transceiver (1RC1) to RMP 1 (1RG1) of the FREQ SELECT INPUT PORT A signal, from pins AB/11A, 11B to pins A/<P, <Q ASM 231302.

Subtask 23-13-00-740-059-A

B. Do the test given in Para. 3.C.

[Rev.8 from Aug 2018] 2026.04.04 04:25:39 UTC