I have an 8 year old Maxtor 40GB hard drive which I've connected to a new motherboard (ASUS P8H67-M PRO). It's for use as a secondary hard drive; I have my OS installed on another one. Well it worked fine until I made the mistake of wanting to try a PCI RAID card (this is something I had bought a while ago but had only tried connecting CD/DVD drives to it: they didn't work). I connected the Maxtor drive to this expansion card through an IDE cable. OS and BIOS didn't detect it.
Then I connected it back to the motherboard just like before and same thing; not detected. Could the expansion card have fried the hard drive through the IDE cable? It doesn't seem plausible since that's a data cable.