This happened after moving M-Card from TiVo HD to new Premier XL4.
Decided to dedicated TiVo HD to OTA viewing and recording, implemented Guided Setup, attached antenna; Tivo made channel search, started download of program info...and suddenly rebooted. After this the infinite loop started: "Powering Up", " Almost there...", "Powering Up", " Almost there..." and so on.
Waited for four hours, tried to disconnect DVR Expander, no change, same infinite loop.
Is there any way to force full startup? Or some loader got corrupted on hard drive and device is a dead meat?