s2kfixit

I just got an FiOS in january. After that my calls are being dropped and during a phone conversation it breaks my voice frequently. I called verizon and they said that there is a loose connection inside the house and its possible that your phone is not compatible to Fios. Is there any way to go back to original Analog line then Fios? Or how should I resolve this. How can I test the connection inside the house? What device I can use to test the loose connection.