Installling Multiple DVD roms

I am trying to install multiple DVDROMs using PCI Ide controller cards. It eas working but since one of the dvdr’s has gone, and I treid to replace it with another one, I have not been able to get the computer to start up again. If I disconnect all dvd(4) drives from the controller card, the computer works fine.
Can anyone please help me with this?

Thanks
geek