I have a system that the loud ring and page quit working. Seems com cast had unplugged power but anyway I was working with a tech and he told me I would have to down grade the software. From 11.0.4000.79 to 10.1.700.4 that just doesn't seem right to me so that is why I'm here to double check. I did put a new V2001a in and can get tone threw the horns also when call ext 16 will ring the horns but call coming in from the outside nothing and checked I do have it on immediate ring. Any ideas? Has anyone ever have this problem?