Just having us format the drive or finding an image somewhere . . .

I think I have now exhausted all things within my capability to restore this unit, I ran the spin rite diag with no errors reported or corrected. In my amatuer opinion I have a mechanically sound hard drive in which somehow the tivo operating system software has some become corrupt. As I have mentioned before I would like to retrieve the 500 + hours of recordings that existed on the drive if at all possible. Is it possible that Weaknees has the ability to either retrieve the recordings and transfer them to another drive or perhaps reinstall the TIVO Software on the malfunctioning drive ... Thanks for any input on this...

I sincerely doubt we could recover the data on the drive, given what you've tried. But I'd guess that a fresh drive with a fresh OS would get it up and running.