If you don't care about the contents, you could just zero the drive with a Linux live boot, using your PC. You don't even need to wait for dd to finish. Just let it run for a bit.
dd if=/dev/zero of=/dev/(your hard drive)
Something similar happened to me. I hit the solder points on the underside of the switchboard itself. I did not see anything obvious. Seemed to work though. In my case, they were not completely dead to begin with. They were not staying on consistently.