Okay, I have replaced the Ring Generator Unit (Part #2993607) and the voltages are perfect. I'm getting +5v and +14.08v. My problem now is that when I first pick up a phone and listen for a dial tone, the dial tone is not steady--it makes the same sound that you would hear if you placed a "do not disturb" feature on your phone. After about 3 seconds, the sound changes to a normal dial tone sound. If you try to dial any extension or "9" to access an outside line, all you hear is the sound you get when a phone line is unavailable. Does anybody know whether this might be the EPB card? I've tried pressing the round black reset button on this card, but no difference.
