My HR24 goes black or shows no communication with the dish on occasion, but it's due to the coax connection on the back. It usually happens if the box gets moved slightly or one of the cats walks on it. It will start working again if I reseat the cable. I would look into getting it fixed or swapping out the box, but both of my DirecTV DVRs will be gone for good when I cancel my service this month.Funny you should mention the black screen, because I have an HR24 that has been doing that on a somewhat irregular basis. Everything just disappears, including the sound. Only a reboot fixes it.