External Drive woes

so I am a student and I bought a Seagate Barracuda 7200 drive and put it inside an external box. It ran fine, then I brought it home for xmas and it ran fine there, then I brought it back to school and it stopped working. I got a replacement, but right after I took out the old drive, on a whim, I put it back in and lo and behold it worked again so i sent the replacement back. I traveled again with the drive and it's not working. i tried removing it from the case and putting it back in to see if it would work again, but it didn't. advice?

 

If you can hook it up as a slave drive to a computer, you can run chkdsk /r from the management consol, but to test your drive seatools for dos is available at majorgeeks
http://www.majorgeeks.com/Seagate_SeaTools_for_Windows_and_DOS_d2858.html
or, go to seagate site and run through its pages for other help
http://www.seagate.com/ww/v/index.j...toid=15c04a3cdde5c010VgnVCM100000dd04090aRCRD

Sorry, have to go, but come back if you need more help, plenty of help, usually, from others at majorgeeks, if I am not around.