Failure Not Clearly Identified - Zone Controller Fault

TASK 21-63-00-810-848-A
Failure Not Clearly Identified - Zone Controller Fault

NOTE: Further information for Zone Controllers Part Number 775D0000-01 with these serial numbers: 1336 to 1340, 1344, 1345, 1347, 1354 to 1356, 1359, 1360, 1362, 1363, 1366 to 1368, 1370 to 1372, 1374, 1376, 1377, 1380, 1381, 1384, 1385, 1387, 1389, 1392 to 1394, 1396, 1397, 1399, 1403, 1405 to 1409, 1411, 1412, 1414 to 1420, 1422, 1431, 1437 and 1462 can be found in Libherr SIL 120.

1. Possible Causes

ZONE CONTROLLER [8HK]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 21-63-34-000-001	Removal of the Zone Controller
AMM 21-63-34-400-001	Installation of the Zone Controller

3. Fault Confirmation
Subtask 21-63-00-710-137-A ** ON A/C NOT FOR ALL

A. This fault cannot be confirmed on the ground.
(1) Do a read out of the Previous Leg Reports (PLR).

4. Fault Isolation
Subtask 21-63-00-810-143-A ** ON A/C NOT FOR ALL

A. If the PLR's give the maintenance message FAILURE NOT CLEARLY IDENTIFIED:
(1) If the message is not repetitive no further trouble shooting is necessary.
(2) If the message is of a repetitive nature,

replace the ZONE CONTROLLER [8HK] AMM 21-63-34-000-001 and AMM 21-63-34-400-001.

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