## 5.2 Common Troubleshooting

Fault Symptom | Possible Cause | Suggested Action
The status indicator is off after the device is powered on. | No power is supplied to the switch or the power cord is loose. | Check whether the power socket in the equipment room is normal and whether the power cable connected to the switch is loose.
An RJ45 port is disconnected or a frame sending/receiving error occurs. | The connected twisted pair cable is faulty. The cable length exceeds 100 m. The port is specially configured and does not use the same work mode as the interconnected switch. | l Replace the twisted pair cable. Check port configurations and whether they work in the same mode as the interconnected switch.
An optical port cannot be connected. | Rx and Tx ends are connected incorrectly. The types of the interconnected optical modules do not match. Fiber type does not meet requirements. The optical fiber length is beyond the allowed length marked on the optical module. | l Connect the Rx and Tx ends of the fiber correctly. l Replace optical modules with those of the same type. l Replace the fiber with a qualified one. l Use an optical fiber with the required length.