8.1 TroubleshootingIf you still have difficulties after following the instructions in this section, disconnect the unit from the ACoutlet, then connect the AC adaptor again. If using PoE, disconnect the LAN cable, then connect the LANcable again.General UseProblem Cause/SolutionThe display is blank. • The unit may not be receiving power.The unit is not designed to function when there is a powerfailure. Make sure that the device supplying PoE isreceiving power and that the Ethernet cable is properlyconnected. (If you are using a PoE hub, the number ofdevices that you can connect simultaneously is limited bythe amount of power supplied by the hub.)If an AC adaptor is connected, confirm that the ACadaptor is connected and receiving power.I cannot hear a dial tone. • Network settings may not be correct.• Many installation issues can be resolved by resetting allthe equipment. First, shut down your modem, router, hub,unit, and PC. Then turn the devices back on, one at atime, in this order: modem, router, hub, unit, PC.• If you cannot access Internet Web pages using your PC,check to see if your phone system is having connectionissues in your area.• Check the VoIP status in the Web user interface andconfirm that each line is registered properly (→ see Tocheck the setting status in the Web user interface inthis section).• Check that the SIP server address, URLs of theconfiguration files, encryption key, and other requiredsettings are correct.• Check the firewall and port forwarding settings on therouter.• For details about the settings, consult your networkadministrator or phone system dealer.8.1 Troubleshooting384 Administrator Guide Document Version: 2017-07
