Phenomenon Description

POWER_ABNORMAL alarm is reported on 2PIU single boards of OSN 1500 equipment, the alarm parameters are 0X01 00 01 00 FF; 0X11 00 01 00 FF respectively

Equipment power supply situation: power supply module (can detect voltage, load) - column header cabinet - OSN 1500 equipment.

Cause analysis

For PIU veneer, the meaning of parameter 1 is as follows: 0x01 means -48V A-channel (default for low-slot PIU veneer) voltage, and 0x11 means -48V B-channel (default for high-slot PIU veneer) voltage; parameter 2 is fixed to 0x00, and parameter 3 is fixed to 0x01, which has no significance; parameter 4 indicates the working status of the power supply: 0x00 means under-voltage, 0x01 means over-voltage Parameter 5 is reserved for use. According to the alarms and parameters, the two -48V voltages are too low, leading to the following possible causes:

External voltage input too low

Power cable problem

PIU single board failure

AUX board failure

Procedure

Test the external voltage, including power supply module, column header cabinet, unplug the power cable of PIU single board, then test the voltage, the normal is -53V;

Replace 2PIU single boards, the fault remains;

As the AUX single board monitoring subrack two independent -48V power supply, and over-voltage ( -72V ) and under-voltage ( -38.4V ) detection and analysis. It is suspected that the AUX is inaccurate in detecting the two -48V voltages and detecting power module failure. Therefore, replace the AUX single board observation, the alarm disappeared, the problem is solved.

Recommendation Summary

OSN 1500 equipment two -48V voltage detection point in the AUX single board, OSN 2500 equipment two -48V voltage detection point in the SAP single board, OSN 3500/7500 equipment two -48V voltage detection point in the GSCC single board, OSN9500 equipment two -48V voltage detection point in the GSCC single board. OSN 3500/7500 devices have two -48V voltage detection points on the GSCC board, and OSN 9500 devices have two -48V voltage detection points on the EMPU board.