Seeing that the hard drives in tivo units are constantly working: buffering incoming live tv data, writing your season passes, playing back recorded programs and erasing old unwanted programs, the hard drives used in tivos are bound to develop bad sectors or corrupt data at some point in time. Wether it be freezing, pixellization, random reboots, or everyone's favorite GSOD (Green Screen of Death), your tivo has many ways of letting you know your hard drive may be in jeopardy.
So for those of you who have the time and technical prowess, here's how to find out if your drive has kicked the bucket and if all of your episodes of Battlestar Galactica have been lost with no chance of recovery.
If you are using a Seagate drive, you can download Seagate's diagnostic tools here
If you are using a Maxtor drive, you can download Maxtor's diagnostic tools here Edit: use the Seagate tools for Maxtor drives now that they are the same company
If you are using a Western Digital drive, you can download Western Digital's diagnostic tools here
and finally, for the few folks that might have a Samsung drive, go here to download Samsung's diagnostic tool