I recently bumped the power cable on my debian server at home. The computer shutdown, and since then hasn't been feeling like going past grub. When I boot the computer it gets to the "Welcome to Grub!" screen, but doesn't load my menu. I booted into a live cd and the hard drive seems intact and accessible. I re-installed grub without any problems, but the same problem is happening. I tried running fsck, but it says that the "device or resource is busy while trying to open /dev/sda". I am kind of stumped and would prefer not to reinstall debian to get this box running. Any thoughts on what I should try? Let me know if you need any more information.

If you want to to fsck on the drive, do it with a live cd. Some live cd's mount the drive automagically for you. Be sure it's not mounted with a "df -h" before running fsck.

Describe the steps to reinstalling grub.

I agree about looking at it with a live cd for clues. Many times you have to run the hard drive's version of the tools however.

Consider also running other diags like ultimate boot cd for memtest and hard drive diags. I suspect it will pass but may be worth it.

Also check bios to see that drive reports and memory is correct in amount.