Figure 6-1 shows the general troubleshooting flowchart.

Figure 6-1  Power supply troubleshooting flowchart 

1. Measure the input voltage. Use a multimeter to measure the input voltage. Check the input voltage against the working voltage range of the power supply.
2. Reinstall the power module. Reinstall the power module and power cable to ensure that they are connected properly.
3. Replace the power module. Install the power module on another device, or install another power module on this device.
   • If the power module is faulty, send it to Huawei for repair.
   • If the device is faulty, contact technical support personnel.

The SYS and PWR indicators of the device are off, and no information is displayed on the serial port.

• The power switch is off.
• The power cable is not properly connected to the device.
• The power module on the device becomes faulty.
• The external power supply of the device becomes faulty.

1. Ensure that the power switch is on.
2. Ensure that the power cable is properly connected to the device.

3. Check whether the external power supply is faulty.

   Replace the external power supply with a new one. If the device can be powered on, the original external power supply is faulty.

4. Check whether the power module on the device is faulty.

   If it is a pluggable power module, replace it with a normal one. If the device can be powered on, the fault is caused by the faulty pluggable power module.

   If it is a built-in power module, contact technical support personnel.

5. If the device still cannot be powered on, the device is faulty. Contact technical support personnel.

Optical module information on the device cannot be displayed, but services are normal.

• A non-Huawei certified optical module is used.

• The optical module is not properly installed.
• The system software version of the device needs upgrading.

 NOTICE:

Removing and installing optical modules, restarting the device, or upgrading the software version will affect services. Therefore, perform these operations when only necessary.

1. Check whether a Huawei-certified optical module is used. If not, replace it with a Huawei-certified optical module.
2. Reinstall the optical module. If the optical module information is displayed, the optical module can still be used.
3. Check the optical module types and operation modes on the two devices. Check whether the single-mode or multi-mode optical modules are used and choose the optical jumpers of the correct type.
4. Run the display version command to check the software version. If the version is earlier than V200R001C00SPC100, you are advised to upgrade the software version to V200R001C00SPC100or a later version.
5. If you choose not to upgrade the software version, restart the device.
6. If the fault persists, contact technical support personnel.

The transmit power of an optical module tested by an optical power meter is lower than the nominal transmit power.

• The optical port is dirty.

• The circuit of the optical module is faulty.

1. Check the optical port on the optical module. If it is dirty, use a cotton swab to clean it, and then test the transmit power again. Use a dust plug to cover the optical port of the idle optical module.
2. If the transmit power is still too low after the optical port is cleaned, replace the optical module or install it in another optical port to check whether the optical module is faulty. If the optical module is faulty, sent it to Huawei for repair or contact technical support personnel.