Try to check the internal connections carefully. My best guess would be a loose wire.

Sorry to butt in on this thread but I am new to this forum and suspect I, also have a power supply problem. I have a Directv R-10 which recently had the dreaded "green screen" error I think. I have previously expanded the memory with a HD addon from Weeknees in the past, so I ordered a new primary 320 Western Digital and installed it with resolution of the problems for 48 hrs. Now, I have a solid blue screen (the same default screen my reciever outputs with no input). If I disconnect the power and restart, I get the powering up screen for about three minutes, then the "almost there" screen for another three minutes, then bluescreen again. I assume the Hard drive is ok, does this sound like a power supply issue?

Do the lights go out on the front when you get the blue screen?

This Am all is working normally. When the blue screen problem appeared, the front lights had a verry very dim flicker in an amber color. If this is working intermittently, and fixed itself without a restart, does that pretty much point to a power supply problem?

Hard to say for sure, but if I were experimenting, that would be the first part I'd replace.