Loss of the ACS2 Signal of the SEC1 MON Side

TASK 27-90-00-810-803-A
Loss of the ACS2 Signal of the SEC1 MON Side

1. Possible Causes

SEC-1 [1CE1]
wiring of the ACS2 signal from the SEC1 MON side to the first terminal block

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 27-90-00-810-801-A	Failure of an Alternating Current Supply (ACS)
ASM 279402
AMM 27-94-34-000-001	Removal of the SEC
AMM 27-94-34-400-001	Installation of the SEC
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)

3. Fault Confirmation
Subtask 27-90-00-740-052-A

A. Test
Do the BITE Test of the EFCS (Ground Scanning) AMM 27-96-00-740-001.

4. Fault Isolation
Subtask 27-90-00-810-052-B

A. If the test gives the maintenance messages:
L SPLR4 POS XDCR 31CE7
and
R SPLR4 POS XDCR 31CE8

remove the SEC1 AMM 27-94-34-000-001.

(1) At the SEC1 receptacle, do a check of the resistance and of the insulation between the pin AD/10G and the pin AD/10H (15 to 250 ohms) ASM 279402.
(a) If the resistance values are in the specified limits:

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

(b) If the resistance is less than 15 ohms:
1 Do the trouble shooting procedure (Ref. TSM TASK 27-90-00-810-801).
2 Replace the SEC-1 [1CE1] AMM 27-94-34-000-001 and AMM 27-94-34-400-001.
(c) If the resistance is more than 250 ohms:
1 Do a check and repair the wiring of the ACS2 signal from the SEC1 MON side to the first terminal block ASM 279402.
2 Install the SEC1 AMM 27-94-34-400-001.

Subtask 27-90-00-740-053-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:39:14 UTC