I have an Extension at a main post (Dterm Series E 16 button on NEAX 2000IVS) that does not ring it answers in voice mode. When you call the extension you never hear it ringing you just instantly hear the people at the post. The manual says Factory Access Code is 60 for Voice/Tone Toggle but I tied that to no avail. Any suggestions how to toggle phone back to answering by ringing? Thanks