I have a Tivo HD upgraded with a 1 TB hard drive. After my building shut off power to replace a feed line (and I forgot to switch everything off before that happened), the TiVo has yet to proceed pass the Welcome! Powering Up screen. I plugged back the original 160 GB hard drive in to get the same result, so I suspect that motherboard or power supply is the concern rather than the hard drive.
I've been considering adding or upgrading to a Premiere or XL4 anyway, but if I do, is there any way to access the recordings on the HD hard drive if that TiVo isn't working?