Troubleshoot hardware

Fan module issues

Abnormal fan module status

Symptom

The LED for the fan module is abnormal or a fault occurs during the fan tray operation.

Common causes

The following are the common causes of this type of issue:

·     The fan is not securely installed.

·     The air outlet and air inlet of the chassis are blocked by foreign objects.

·     The fan hardware is faulty.

Troubleshooting flow

Figure 1 shows the troubleshooting flowchart.

Figure 1 Flowchart for troubleshooting fans

Solution

1.     Identify whether the LEDs for fan modules are normal. The fan LED status varies by device model. For details, see the hardware manual for the corresponding device. If all LEDs are off, identify whether the power modules operate normally or whether the switch wiring of the chassis is open. For more information, see the power module troubleshooting guide.

2.     Check the fan tray state.

Use the display fan command to check the fan tray state.

<Sysname> display fan

Index  Status     Speedlevel

 ----------------------------

1      Normal     24%

You can also use the display alarm command to check fan tray alarm information.

<Sysname> display alarm

Slot   CPU   Level   Info

-       -    INFO    fan 1 is absent.

3.     Identify whether the fan tray is securely installed.

4.     If the state of the fan tray is Absent, the fan tray is not in place or not installed securely. If the fan tray is present, reinstall the fan tray. Before you reinstall the fan tray, identify whether the fan connector is intact. Then, identify whether the fan tray state is Normal. If the fan tray state is still Absent, replace the fan tray. If the fan tray state is still Absent after replacement, proceed to step 7.

5.     Check the device's working environment information.

6.     If the state of the fan tray is Fault, the fan tray is abnormal and cannot provide heat dissipation via air exhaust. Follow these steps for further troubleshooting:

a.     Use the display environment command to check if the system temperature keeps rising. If the system temperature keeps rising, feel the air outlet of the device with your hand to identify whether air is flowing out. If the temperature keeps rising and no air flows out of the vent, the fan tray is abnormal.

b.     Identify whether the chassis air outlet and air inlet are blocked by foreign objects. If there is any foreign object, clear it.

c.     Identify whether the rotation speed of each fan is normal.

-     Execute the display fan command in any view to identify whether the speed of each fan differs from the normal speed by over 50%. If any abnormalities exist, reinstall the fan tray or install the fan tray in another slot to further identify whether the fan tray is abnormal.

d.     If the fan tray is abnormal, reinstall the fan tray. Before you reinstall the fan tray, identify whether the fan connector is intact. Then, use the display fan command to identify whether the fan state recovers to Normal.

e.     If the fan fails to recover to Normal, replace the fan tray. If the fan tray is unavailable on site, you cannot replace it immediately. Power off the device to prevent circuit damage from high temperature. If cooling measures ensure the system operates below 50°C (122°F), you can continue using the device.

f.     If the fan fails to recover to Normal, proceed to step 7.

7.     If the issue persists, collect the following information and contact Technical Support:

¡     Results of each step.

¡     The configuration files, log messages, and alarm messages.

Related alarm and log messages

Alarm messages

N/A

Log messages

·     DEV/2/FAN_FAILED

·     DEV/3/FAN_ABSENT