The MVP110 will either not give a dial tone or not have any audio after connection.

If the MVP110 is powered down and then backup without waiting 10 seconds, the MVP110 will either not give a dial tone or not have any audio after connection.
You have two options:
1 Make sure the power is off for a minimum of 10 seconds before turning it back on.
2 You can send the Voip in to the factory repair department for a hardware modification.