DWDM Products

Cautions on the Flash Memory Failure in DWDM Products

Summary: Because of defective incoming materials, the Spansion Flash memory units provided in a specific lot cannot erase Flash memory data. Huawei transmission boards equipped with these Flash memory units occasionally encounter a software uploading failure, patch upgrade failure, or log recording failure; or the boards sometimes reset unexpectedly or fail to boot from a reset.

 DWDM Products
[Problem Description]

Trigger condition: The problem corresponding to this rectification notice is likely to occur when a board listed in the attachment is undergoing an upgrade/reset or backing up logs because of a Flash memory erasing failure. The probability increases with the frequency of erasing the Flash memory.

Symptom: Upgrade failure: When an involved NE is undergoing a software or patch upgrade, the U2000 displays that loading the software or installing the patch has failed.

1.Backup failure: An SCC board backs up the database every 30 minutes. When an involved SCC board attempts to back up the database after a configuration change occurs in the database, the attempt fails and the board reports a DBMS_ERR alarm. The new configuration is lost after the NE is reset.

2. Unexpected reset or failure to boot from a reset: An involved board is reset upon a component failure. During the restart from the reset, the board performs a Flash read/write check and fails to boot. Identification method: The boards in the attachment are at the risk of having this problem.

[Root Cause] The production process of Spansion is not well controlled. Due to production errors, the grating oxide layer on the Flash chip wafer is uneven. Horizontally, the oxide layer has become thinner because of corrosion. In a high voltage application (programming or Flash erasing), the oxide layer will be punctured and consequently erasing the Flash memory will fail. For a board equipped with a Spansion Flash memory unit, the Flash memory is erased when the board is undergoing an upgrade/reset or is backing up logs. The probability that the board fails to boot increases as the Flash memory is erased more often.

[Impact and Risk] 1.The boards listed in the attachment will occasionally encounter a software uploading failure, patch upgrade failure, or log recording failure; or the boards sometimes reset unexpectedly or fail to boot from a reset. 2.The following table provides the failure rate for each involved board.
[Measures and Solutions] Replace all the boards listed in the attachment.

Preventive measures: Replace all the boards listed in the attachment. The following table provides the board information provided in the part number library.

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