So I'm trying to fix my brothers computer and for some reason the computer will not recognize any of the 3 hard drives it has. Also, when any of the three hard drives are plugged in, the computer will not go past the post screen. I've rotated the hard drives as well as switch the jumpers around from slave to master etc. Nada..and its not the motherboard or cpu. the only way i can get past the post screen and into the bios is to remove all 3 the hard drives. i placed a hard drive from my own pc into my bro's computer and it recognizes it. but when i place any of the 3 hard drives from my bro's pc into my own pc, my pc will not boot up, it freezes at the post screen. I tried moving the jumpers around for this as well but nothing worked. Any thoughts on whether the hard drives are toast or not? or if there's any way to retrieve the data from them?