Sometimes the magnet just erases the hard-drive (Actually it's always I think) but you might be able to plug it into your computer and re-install the firmware. You'll need to download it from creative.com if it's available.
Eitherway, the firmware probably got erased meaning it doesn't have a program to make it function anymore. You need to download the firmware again (usually free from maker) and re-install it via your computer.
As for anything else, I'm at a loss.
Stewie2kill
May 2008