6. Troubleshooting193If you find any problems, please take the following steps to check.◆ LED■ The POWER LED (Power) is not lit.● Check if the power cord is disconnected. Please confirm that the powercord is securely connected to the power port● Is the Switching Hub being used at a temperature between 0 and 50degrees C? Use the Switching Hub in its operating temperature range.Note: If used at a temperature out of the operating temperature range, theprotection equipment becomes activated and PoE power supply stops.Thedefault operating temperature range is 0 to 50 degrees C.■ The Port LED is not lit in Status mode.● Is the cable correctly connected to the target port?● Is the cable appropriate to use?● Is the terminal connected to the relevant port conforming with 10BASE-T,100BASE-TX, or 1000BASE-T standard?● Auto-Negotiation may have failed. Check the port settings of this Switch-ing Hub or the terminal settings.■ The Port LED (Left) lights in failed.Check the port settings of this Switching Hub or the terminal settings.■ LOOP HISTORY LED Blinks in green.● This is no notify that there is a port in which a loop is occurring, or hasbeen removed within 3 days.◆ Communications are slow.● Are the communication speed and mode settings correct? If the propercommunication mode signal cannot be obtained, apply half-duplex mode.Please reconfirm auto negotiation setting.● Is not the utilization ratio of the network to which this Switching Hub isconnected too high? Try separating this Switching Hub from the network.◆ Communications fail.● Is the link-up correct? If embedded saving mode is set to Full, change thesetting to Half or Disabled.● Is the Port LED (right) lit in orange? If the Port LED (right) lit in orange, theport is shut down by the loop detection function. Eliminate the loop con-nection of the device connected to the port first, and then wait longer thanthe time required for automatic recovery from the shutdown by the loopdetection function, or release the port shutdown from the setting screen.
