We currently have a Partner ACS R4.0 C1 Phone system. Last week, randomly, ext 27 just stopped working, in fact the phone itself stopped working. At first I thought maybe it was the phone, changed phones and nothing...then I changed the cable...nothing. I finally simply connected the phone directly into the unit itself...same thing. The phone display back light turns on for a second and then shuts off, and then keeps repeating that. I'm hoping someone out there has an idea. I have read through all the manuals and I cant find anything where someone has the same issue. I can remotely connect into the phone system through the administration software but I really don't know what i'm looking for.