My TiVo HD went into a boot loop, rebooting from the "Welcome!" screen. I couldn't get to the kickstart screen, so I tested the hard drive in a PC and it was fine. I had replaced every capacitor in another TiVo HD with no success so I was skeptical of fixing this one. This power supply had two bulging capacitors (2200uF at 6V). The voltages were all good, but since swollen or leaking capacitors are always bad, I replaced both with 2200uF 35V parts I had on hand. The TiVo works now. There are three positions on the PC board for these capacitors. The manufacturer had used the two closest together. I used the two furthest apart because the 35V capacitors are larger in diameter. Before the repair, the power supply DC voltages tested good with a DMM, with no measurable AC component. After the repair, there was no change in the measured DC voltages. I can speculate that the bad capacitors allow enough high-frequency ripple on the DC line to distort the data, but I did not test with a 'scope to find out before changing the parts.