Both PIU boards have POWER_ABNORMAL alarm due to the AUX board faulty

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Issue Description

The Huawei OSN 1500 starts to has POWER_ABNORMAL alarm in both PIU boards.

[url=(http://www.thunder-link.com/HUAW ... 01.html?search=1500)](http://www.thunder-link.com/HUAW ... 01.html?search=1500)[/url]

Alarm Information

After get the data collector of the equipment we found that the alarm has the following parameters:

1   POWER_ABNORMAL    MJ   start  2012-05-03 16:14:14  None   0x01   0x00   0x01
0x00  0xff

11    POWER_ABNORMAL  MJ  start   2012-05-03 16:14:14  None    0x11   0x00   0x01   0x00   0xff  

Handling Process

After analyze the information collected with GTAC, we found that the root cause of the alarms may be is the Huawei AUX board, Huawei GSCC board or Huawei PIU board. With following steps we can determinate which board is the root cause:
(http://www.thunder-link.com/index.php?route=product/search&search=AUX

http://www.thunder-link.com/index.php?route=product/search&search=GSCC

http://www.thunder-link.com/index.php?route=product/search&search=PIU)

1. The external power supply may has the under-voltage problem or fluctuates sharply. So need to measure and confirm the external power supply for this Huawei OSN1500 is normal and stable.
If the standard voltage of the input power supply is -48 V, and the measured value should be in the range of -41 V to -60 V;If the standard voltage of the input power supply is -60 V, and the measured value should be in the range of -51 V to -72 V;

2. If confirm the external power supply is normal and stable, check whether there is any pin bent in slot for AUX board; if no, replace AUX;

3. If AUX board and its slot are normal, check GSCC boards:
(1). plug-out the standby GSCC, 82-GSCC(4-CXL1);[PAY ATTENTION: plug-out this board could cause service affection]check whether POWER_ABNORMAL alarm disappear;

(2). If alarm exist, re-insert 82-GSCC and switch GSCC, then plug-out current standby GSCC, 83-GSCC(5-CXL1); [PAY ATTENTION: plug-out this board could cause service affection] check whether POWER_ABNORMAL alarm disappear;

4. If alarm still exist after plug-out both two GSCCs, check PIU boards: plug-out one PIU, check whether corresponding POWER_ABNORMAL alarm disappear, if yes, replace the PIU; and then plug-out another PIU with same way;

After review the possible causes, we found that the root cause of the alarm was the AUX board, after replace the board the issue was solve.

Root Cause

The customer needs to know the root cause ot this alarm ands also knows if the PIU baords are OK, also the customer informs that the same issue appears in another OSN 1500.