MY DVR just died

My  U-verse DVR-receiver just died. It does not respond to any command. The only sign of life is a light glow of the link and record lights on the front of the unit. I left it un-powered for 9 hours and when power was restored the unit appeared to be working except that no function had video. When I powered the unit down it returned to its dead state.

I think I need a new DVR-Receiver. Any  suggestions? How (who) do I request a replacement?