A few months ago one of my older external hard drives stopped working. When I plugged it in to the PC Windows recognized something was connected, but wouldn't read the drive. I tried plugging it into a PC loaded with Linux, but that didn't work either. I could live without the data on the drive, but I still wanted it all back. I came up with an idea to swap out the logic board (controller) with a similar model from Western Digital. I spent several months looking on Ebay for the same model and last week I finally found one. There were some other annoying bidders jockeying for the same hardware and when the auction was over I ended up paying more than the drive was worth.
After the new/used drive arrived I switched out the logic boards. Afterwards I plugged in the original hard drive, but nothing happened. I know the logic board from Ebay worked, because I tested it before I removed it from it's case. Disappointed I installed the good logic board back onto it's drive and plugged it in...nothing but a very audible clicking noise. I think I managed to break the good drive too.
So I now I've got two Western Digital paper weights taking up space in one of my junk drawers. Fantastic.