Loss of the Signal of the Left Blue Elevator-Servocontrol Servovalve by the SEC 1

TASK 27-30-00-810-808-A
Loss of the Signal of the Left Blue Elevator-Servocontrol Servovalve by the SEC 1

1. Possible Causes

SEC-1 [1CE1]
XDCR UNIT-ELEV POS, L [49CE1]
servovalve of the servocontrol 34CE3
SERVO CTL-L ELEVATOR, OUTBD B [34CE3]
wiring of SV XDCR (LVDT) V1 signal from the servocontrol (34CE3) to the SEC 1 (1CE1)
wiring of the SV XDCR (LVDT) SPLY signal from the servocontrol (34CE3) to the first terminal block
wiring of the POS XDCR MON (RVDT) signal from the transducer unit (49CE1) to the SEC 1 (1CE1)
wiring of the POS XDCR COM (RVDT) signal from the servocontrol (34CE3) to the SEC1 (1CE1)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 27-34-51-000-001	Removal of the Elevator Servo Control
AMM 27-34-51-000-008	Removal of the Elevator Servo Control Actuator Servo Valve
AMM 27-34-51-400-001	Installation of the Elevator Servo Control
AMM 27-34-51-400-003	Installation of the Elevator Servo Control Actuator Servo Valve
AMM 27-92-13-000-001	Removal of the Elevator Position Transducer-Unit
AMM 27-92-13-400-001	Installation of the Elevator Position Transducer-Unit
ASM 279407
AMM 27-94-34-000-001	Removal of the SEC
AMM 27-94-34-400-001	Installation of the SEC
AMM 27-96-00-710-020	Operational Test of the Side Stick Assembly (Activation for the BITE Test)
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)

3. Fault Confirmation
Subtask 27-30-00-700-060-A

A. Test
(1) Do the operational test of the side stick assembly (Activation for the BITE test) AMM 27-96-00-710-020.

NOTE: Before you start the operational test procedure, release the FLT CTL/ELAC 1, FLT CTL/ELAC 2 and FLT CTL/SEC 2 pushbutton switches (on these pushbutton switches the OFF legends come on).

(2) Do the BITE test of the EFCS (ground scanning) AMM 27-96-00-740-001.

4. Fault Isolation
Subtask 27-30-00-810-055-B

A. If the test gives the maintenance message:
SEC1 MON OR WIRING TO L B ELEV SERVO VLV 34CE3

Replace the SEC-1 [1CE1] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.

(1) If the fault continues:
(a) Replace the XDCR UNIT-ELEV POS, L [49CE1] AMM 27-92-13-000-001 and AMM 27-92-13-400-001.
(2) If the fault continues:

Replace the servovalve of the servocontrol 34CE3 AMM 27-34-51-000-008 and AMM 27-34-51-400-003.

(3) If the fault continues:
(a) Replace the SERVO CTL-L ELEVATOR, OUTBD B [34CE3] AMM 27-34-51-000-001 and AMM 27-34-51-400-001.
(4) If the fault continues:
(a) Do a check of the wiring of SV XDCR (LVDT) V1 signal from the servocontrol (34CE3) to the SEC 1 (1CE1) ASM 279407:

If there is continuity, see Para. (b)
If there is no continuity, repair the above wiring.

(b) Do a check of the wiring of the SV XDCR (LVDT) SPLY signal from the servocontrol (34CE3) to the first terminal block ASM 279407:

If there is continuity, see Para. (c)
If there is no continuity, repair the above wiring.

(c) Do a check of the wiring of the POS XDCR MON (RVDT) signal from the transducer unit (49CE1) to the SEC 1 (1CE1) ASM 279407:

If there is continuity, see Para. (d)
If there is no continuity, repair the above wiring.

(d) Do a check and repair the wiring of the POS XDCR COM (RVDT) signal from the servocontrol (34CE3) to the SEC1 (1CE1) ASM 279407.

Subtask 27-30-00-700-061-A

B. Do the tests given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:27:30 UTC