OptiX OSN3500 OptiX OSN 6800 OptiX OSN 3800

Operation Steps

1. After checking the history of alarms for this network element, it is found that the multiple single boards that failed initially reported a TEMP_OVER alarm, and then a HARD_BAD alarm, and then the service was interrupted. On the subrack, the temperatures of the corresponding four single boards were found to be 119°C, 119°C, 82.6°C, and 72.7°C. These four single boards were constantly resetting and could not work normally.
2. The OptiX OSN 6800 device is equipped with a fan board, which can automatically adjust the speed to regulate the internal temperature of the device. The fan board was queried to be running at a high speed and the device temperature was still high. It is hypothesized that there is a problem with heat dissipation on this subrack.
3. On-site inspection found that the machine room is dusty, the faulty single board where the equipment is covered with dust on the dust net, the air inlet is blocked, poor heat dissipation performance, the faulty single board temperature is very high. According to this judgment, due to the dust net air inlet is blocked by dust, equipment heat dissipation is reduced, resulting in a gradual increase in the operating temperature of the business board, reported TEMP_OVER alarm. As the maintenance personnel did not timely exclude the high temperature alarm, the single board for a long time running at high temperatures, ultimately leading to device burnout business interruption.

Operation Result

References

A summary and recommendations on this case are provided below:

• Maintenance personnel should regularly clean the equipment dust net to ensure that the equipment has better heat dissipation conditions.
• When a single board reports a TEMP_OVER alarm, pay enough attention to it and troubleshoot the problem in time. Consider whether the fan speed is set incorrectly or the dust net air inlet blockage reduces the cooling capacity.
• Clear the alarms on the current network in time.