I Have No Dial Tone But Have Internet And Cable

• Unplug the power from the modem. 
• On the bottom on the modem is a battery compartment; remove the lid and take out the battery. 
• There should be a plastic tongue holding the battery in place - hold that to the side and then slide the battery out.  ( if there is no battery that is ok)
• Make sure you leave the battery out for at least 60 seconds. 
• Put the battery back into the modem and plug in the power cord.

Once power is restored you should see the lights all come on, then all flash off.  The lights will then start to come back on one-by-one.  Once the Power, DS, US, and Online lights are solid then the Tel1 and Tel2 lights will begin to blink.  At that point wait for about 20 seconds and then dial tone should be restored.