When anyone calls my MJ number, they get a busy tone (no VM either). On my side, i hear no ring, just 1 click. If i pick up at the sound of the click then the call is good but if i m late then the call gets disconnected.
sounds like the phone you have hooked up to it is using too much juice when it tries to ring. try another phone or unhook it from your entire house lines and give it another shot. might also try a powered USB hub if all else fails
Somethins similar to this Just make sure is says power supply included orits called a powered Hub. This may give the jack the added juice its looking for if this is indeed the problem