73If you find any problem, please take the following steps to check.◆ LED indicators■ The power LED (POWER) is not lit.● Is the power cord connected? Please confirm that the power cord issecurely connected to the power port.● Use the Switching Hub within the range of operating temperature.■ The port LED is not lit on the Status mode.● Is the cable correctly connected to the target port?● Is an appropriate cable used?● Is a 10BASE-T, 100BASE-TX, or 1000BASE-T terminal connected to the tar-get port?● Auto-negotiation may have failed.→ Set the port of this Switching Hub or the terminal to half-duplex mode.■ The port LED (Right) is lit solid orange.● A loop is occurring. When you recover the loop, solid orange LED is turnedoff.■ LOOP HISTORY LED is flashing green.● There is a port having a loop or a port on which a loop was recovered lessthan 3 days ago.◆ Communications fail.■ Communications with all ports are down or slow.● Are the communication speed and mode settings correct?→ If the communication mode signal cannot be properly obtained, applyhalf-duplex mode.Switching Hub the communication mode of the connection target tohalf-duplex mode.Do not fix the communication mode of the connected terminal to full-duplex mode.● Are the ports linking up?→ If the MNO series power saving mode is set to "Full", try setting it to"Half" or "Disabled."● Is the bandwidth usage rate of the backbone network to which thisSwitching Hub is connected excessively high?→ Try separating this Switching Hub from the backbone network.● Is the port LED (Right) lit solid orange?→ If the port LED (Right) is lit solid orange, the port is being blocked by theLoop detection and blocking function. After the loop was recovered inthe port, wait for more than the recovery time until a port starts to beautomatically recovered, or release the blocked port on the configura-tion screen.5. Troubleshooting