First, please check if your phone has been set to pulse mode or Tone mode. The VOIP Phone Box is not working under pulse mode.
In addition, if you using your own wireless router, please remove the router and connect the WAN port of the phone box directly to the modem. The phone set is connected to the Phone1 of phone box. Then restart all devices and check if the phone is working properly.
If you have tried all of the above, but the phone still does not work, please contact our technical support.