Summary:
0.03% to 0.1% of certain models of data boards and central switching boards with the basic BIOS version of 1.21 or earlier on OSN 550/500 NEs fail to start up after the NEs are upgraded, which results in the rollback of the NE version. The issue is solved after the boards are replaced.

Huawei OSN 550Trigger conditions:
This problem may occur if the following conditions are met at the same time:
An NE is upgraded.
The NE uses one of the following boards: TNH1EM6T/F, TNM1EF8F, TNH1CSHDA/B, TNM1PCXLG, TNM1PCXX, TNM1PCXLX, TNM1PCXGB, or TNM1PCXGA.
The basic BIOS version of the board is 1.21 or earlier.
Symptom:
The faulty board stays in the BIOS state after an upgrade and does not start up. The fault is cleared after the NE version is rolled back.
Identification method:
1. Query the version
2. After an upgrade, the STAT indicator on the board is red and the other indicators are off, which indicates that the board stays in the BIOS state and fails to start up. The board starts up after the NE version is rolled back.
The following interfaces are displayed in the case of an automatic rollback after an upgrade failure on the U2000.When both of the preceding conditions are met, the fault can almost be identified.
[Root Cause]
On the basic BIOS of version 1.21 or earlier, the time sequence of the CPU adder is not the optimal configuration. As a result, there is a low possibility that the board fails to start up after an upgrade.
[Impact and Risk]
The board does not start up after an upgrade, which results in service interruptions. The fault is cleared after the NE version is rolled back.
[Measures and Solutions]
The fault is automatically cleared after the NE version is rolled back.
Solution:
The basic BIOS of boards on OSN 500/550 cannot be upgraded online. If the fault occurs on an NE during an upgrade, replace the board with a new board with the basic BIOS version of 1.22 or later.
Material handling after replacement:
Return the replaced board to Huawei, if the board supplied by thunder-link.com, then please contact your sales representative.