Description of the problem

1, a day, the customer feedback OSN 3500 equipment main control board reported TEMP_OVER alarm, the scene touch the equipment veneer panel feel really big heat!

2、Query the temperature of the equipment, two main control temperature of about 70 degrees or so

3, alarm TEMP_OVER generated by the following possible causes.

Reason 1: too much dust accumulated in the dust net.

Cause 2:The fan stops working.

Cause 3: Refrigeration (heating) equipment malfunction, resulting in high (low) ambient temperature.

Cause 4: Failure of veneer.

Cause 5:Temperature alarm upper and lower limits are not set in accordance with the actual situation

Cause 6:There are other heat sources around the device

Alarm Message

Only TEMP_OVER alarm, no other alarms.

Processing

1, check the equipment dust net, the customer said that the first 2 days before the dust net cleanup, dust net no dust, exclude dust net dust blocking the air inlet

2, check the fan can work normally, the outlet has a hot wind blowing, and use the command line cfg-get-fanspeed command query fan speed for high-speed, to rule out the fan does not turn the problem

3. The air conditioner in the server room is working normally, and the current temperature of the server room is 25 degrees, which excludes the problem of external environment.

4、Query the temperature of several single boards, the temperature is high, to rule out single board failure.

5, check the alarm threshold settings, set to 55 degrees, threshold normal

6, no other heat source in the server room site, to rule out the heat source problem.

7, after suggesting that the customer will be empty slot panel pull out, the use of electric fans on the equipment to cool down, there is a certain effect, the temperature is reduced to more than 40 degrees, the alarm disappeared, without any other alarms!

8, after the preparation of fan spare parts, on-site investigation to confirm that the customer to clean up their own dust, the equipment fan is also cleaned up, followed by the installation process, the fan below the layer of fan blades installed in reverse, resulting in the equipment can not be normal heat dissipation

Root cause

After cleaning the fan, the customer will fan fan blade installed in reverse, resulting in the equipment can not be normal heat dissipation, the equipment temperature rises

Solution

The problem was solved after the customer changed the fan blades back.

Suggestions and Summary

For routine maintenance, cleaning the fan is a non-essential action, daily cleaning of the dust net can be. For disassembling the fan and other operations, it is certainly not recommended that customers operate on their own. If the fan is manually damaged, it is impossible to provide spare parts service. We suggest that our engineers can empower our customers to avoid improper operation causing equipment failure.

This chapter of related technical information and SDH equipment troubleshooting procedures provided by Shenzhen Optical Transmission Network Technology Co. Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales