Description of the problem

Huawei OSN1500 devices report power_abnormal alarms on AUX and PIU at the same time on a certain day, and then a stable power_abnormal alarm is reported at the end.

The alarm parameters are as follows:

Alarm Parameters

AUX power_abnormal 0X01 0X00 0X01 0X01 0XFF

18-PIU power_abnormal 0X01 0X00 0X01 0X01 0XFF

19-PIU power_abnormal 0X11 0X00 0X01 0X01 0XFF

Device version: 5.21.19.22

Alarm information

Board Alarm Parameters

AUX power_abnormal 0X01 0X00 0X01 0X01 0XFF

18-PIU power_abnormal 0X01 0X00 0X01 0X01 0XFF

19-PIU power_abnormal 0X11 0X00 0X01 0X01 0XFF

Processing

1. First of all, the customer found a colleague in charge of the power supply department, checked the power supply equipment, and there was no abnormality.

2. Measured the input voltage of the two PIU power supply lines with a multimeter respectively, and the input voltage was -53V, without any abnormality.

3. The ambient temperature of the machine room is good, and the dust net of the equipment is drawn out, and the dust net is relatively clean.

4. Focus on suspected AUX single board failure, replaced the AUX single board to observe a period of time, the failure did not recur.

Root cause

1. First, analyze the alarm parameters, AUX 0X01 0X00 0X01 0X01 0XFF

para0: fixed to 0x01;

para1: fixed to 0x00;

para2: fixed to 0x01;

para3 (converted to binary, bit is valid for 1):

bit0 // Read 1.5V voltage status abnormality of this board

bit1 // Read 1.8V status abnormality of this board.

bit2 // Abnormal reading of the 3.3V voltage status of the power supply module on this board.

bit3 // Abnormal status of backup power supply 3.3V.

2. For PIU single board power_abnormal 0X01 0X00 0X01 0X01 0XFF analysis, the parameter meanings are as follows:

0x01 means -48V A-channel (default for low-slot PIU single board) voltage.

0x0D indicates that the lightning protection voltage of A road is invalid.

0x11 indicates -48V B-way (default for high slot PIU veneer) voltage.

0x12 indicates B-way lightning protection voltage failure.

0x00 indicates undervoltage.

0x01 indicates overvoltage.

0xFF is the default value and is meaningless.

The above alarm parameters are analyzed as voltage overvoltage.

3. Query the document found OSN1500 equipment two -48V voltage detection point in the AUX single board.

The possible causes are:

1. Power input is too high

2. Ambient temperature problem

3.AUX single board failure

4.PIU failure

Suggestions and Summary

1 . OSN1500 devices have two -48V voltage detection points on the AUX single board, OSN2500 devices have two -48V voltage detection points on the SAP single board, OSN3500/7500 devices have two -48V voltage detection points on the GSCC single board, and the OSN9500 devices have two -48V voltage detection points on the EMPU single board. OSN9500 devices have two -48V voltage detection points on the EMPU single board.

2. POWER_ABNORMAL alarm is a power failure alarm, basically all boards will report, this alarm is generally a power failure of the board, to rule out false alarms can be solved by replacing the board. POWER-FAIL is a power failure alarm, this alarm is generally only reported on the main control board, often because the main control board on the battery runs out of alarms, this alarm does not affect the business, replacement of the main control board can be resolved.

3, PIU board POWER_ABNORMAL is often due to power overvoltage or undervoltage.

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