SAP board failure causes the PIU board to falsely report the POWER_ABNORMAL alarm, and the alarm is eliminated after replacing the SAP board.

Products

OptiX OSN2500

Fault category

POWER_ABNORMAL

Description

The OSN 2500 has a 1+1 backup for the power input unit, and the backup 23-PIU board reports a POWER_ABNORMAL alarm.

Cause Analysis

The OSN 2500 monitors two independent input power supplies from the subrack through the SAP veneer. The device supports -48V/-60V voltage input, and the input voltage is set through the J9 and J10 jumpers on the SAP single board:

Unplugged jumper cap: the device uses a power supply with an input voltage of -60V and a power supply voltage between -48V and -72V.

Insert jumper cap: The system uses a power supply with an input voltage of -48V and a power supply voltage between -38.4V and -57.6V.

When the input voltage is out of the above range, the PIU veneer will report the POWER_ABNORMAL alarm. If the SAP veneer fails, it may also cause this alarm to be reported.

Procedure

Test the input voltage of OSN2500 at the site and it shows normal.

Reset the SAP board, the alarm does not disappear, suspect SAP hardware failure.

Replace the SAP single board and the alarm disappears, proving that the SAP single board is faulty.