Loss of the Power Supply 26VAC of the Yaw Damper Side 1

TASK 22-63-00-810-807-A
Loss of the Power Supply 26VAC of the Yaw Damper Side 1

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 226701
AMM 22-91-00-710-001	Ground Scanning of the AFS
AMM 27-26-51-000-001	Removal of the Yaw Damper Servo Actuator
AMM 27-26-51-400-001	Installation of the Yaw Damper Servo Actuator

3. Fault Confirmation
Subtask 22-63-00-710-064-A

A. Test
(1) Do the Ground Scanning of the AFS AMM 22-91-00-710-001.

4. Fault Isolation
Subtask 22-63-00-810-058-A

A. If the test gives the maintenance message AFS : 431 XPA BUS BAR:

replace the SERVO ACTR-YAW DAMPER, 1 [3CC1] , AMM 27-26-51-000-001 and AMM 27-26-51-400-001.

(1) If the fault continues:

do a check of the wiring of the 26VAC signal at yaw-damper servo-actuator (3CC1) from pin A/A to the first terminal block ASM 226701.

(a) If there is no continuity:

(b) If there is continuity:

do a check and repair the wiring of the ground signal at yaw-damper servo-actuator (3CC1) pin A/L ASM 226701.

Subtask 22-63-00-710-065-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:25:14 UTC