I have a Philips DSR708 that I'm trying to rescue from my Dad's house after it failed. When I brought it home and tried to powerup, there was no video output and the rear cooling fan was running. I opened the case, pulled the hard drive (an 80GB WD) to test in a PC. It passes all tests using either the WD diagnostic or Seagate Seatools. After reinstalling the drive in the Tivo, I found that it was not spinning up the drive. A check of +5V and +12V power with the drive connected read fine. However, I found that if I leave drive power connected but disconnect the ide ribbon cable, the drive spins up! So there's something about having the drive connected to the motherboard that prevents normal drive startup. With the ide cable disconnected, the video out gives a few screen flashes when power is applied, but never displays the first "powering up" screen.

I searched this forum for clues, and found one very interesting one in the General Help section, sosb on 7-7-08. sosb included a picture of a power supply with a burned resistor. I looked at mine and it has a nearly identically burned power resistor in its supply. Just like in the picture, mine has brown goo and the resistor has a brown streak from overheating. I'm thinking the power supply is fried, not the motherboard, and the drive is probably OK.

What do you think? Can I rule out the motherboard as failed? Is there some way to check power going to the motherboard? I don't see any labeling to discern what pins are supposed to be a certain voltage.