I am having the exact same problems. I cannot watch TV or my DVR anymore after all of the storms that we had a New York two weeks ago. Every time I turn on the set-top box, it flashes and he on the display and reboots. Really frustrating. I can watch TV on another TV with a non-DVR set top box, so know that the wires are not an issue.
Is there a fix for this, or do I just need to get a new set up DVR box and lose all of the recorded programs that I have. I am thinking it might just be easier to switch over to optimum since they are cheaper and had no problems when I was with them. It should not be this hard to watch TV.