Loss of the Audio Signal from the Marker Receiver of the VOR/MKR Receiver 1

TASK 34-55-00-810-818-A
Loss of the Audio Signal from the Marker Receiver of the VOR/MKR Receiver 1

1. Possible Causes

RECEIVER-VOR/MKR, 1 [3RS1]
AMU [1RN]
wiring of the MARKER AUDIO bus from the AMU (1RN) to the VOR/MKR receiver 1 (3RS1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-51-34-000-001	Removal of the Audio Management Unit (AMU) (1RN)
AMM 23-51-34-400-001	Installation of the Audio Management Unit (AMU) (1RN)
AMM 34-55-00-720-001	Functional Test of the VOR/MKR
ASM 345501
AMM 34-55-31-000-001	Removal of the VOR/MKR Receiver
AMM 34-55-31-400-001	Installation of the VOR/MKR Receiver

3. Fault Confirmation
Subtask 34-55-00-720-060-A

A. Test
(1) Do the functional test of the VOR/MKR AMM 34-55-00-720-001.

4. Fault Isolation
Subtask 34-55-00-810-077-A

A. If there is no audio signal on the loud speakers during the test, when the MKR data are shown on the PFD:

(1) If the fault continues:

(a) If the fault continues:

do a check and repair the wiring of the MARKER AUDIO bus from the AMU (1RN) to the VOR/MKR receiver 1 (3RS1) ASM 345501.

Subtask 34-55-00-720-061-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:33:31 UTC