PC won't recognize extra hard drives (edi) primary is SCSI drive

This is my first attempt at building my own pc so forgive me if this is a silly question.

This pc has an SCSI as the primary drive (17gig) and I'm trying to add two 320g drives that are edi drives.

I added a new dvd drive, video card, and usb 2.0 card and those all work fine.

I tried the drives set to slave as well as well as cable select. I even removed one of the drives so that the only connector is the edi slave connector.

Am I having a problem because I'm trying to use an SCSI drive and the two edi drives? Do I need to use one or the other in order for this to work?

Any help would be greatly appreciated.

Let me give a little more information if it helps. The computer is a Dell Precision 530 Workstation. Company upgraded all their pc's and sold off the old ones for $50 each. I want to ue this as a media server for my home network.

It has a 17GB SCSI drive on it now that has my Windows XP Home Edition and a few other programs on it. I was going to keep it for exactly what it does now. Basic everyday pc duties.

I wanted to add two bigger drives for storage. The mother board has an SCSI connector and two EDI connectors. The secondary EDI connector is connected to the DVD drive and the CD drive. Obviously I don't need both but just left the cd drive in there since it wasn't hurting anything. Those both read and work fine.

I have the two 320 GB storage drives connected to the primary EDI connector.

The ribbon cable attached to the SCSI main drive have three unused connectors and another device attached to the connector on the drive that appears to be an active connector. I have no idea what the connectors do but I did a search on the web and what I have looks like a picture I saw of an active connector. That may or may not be right. Just trying to give as much information as I can. I have also updated my profile to give as much detail as I could on this system.

I thought this would be a simple plug and play deal but the drives aren't being read. I no PC expert by any means but I hit F2 when the system was booting to see if I could find the drives showing up anywhere. Not sure what I as looking for but it did list the main drive durin boot up but not the others.

Ok now I tried to take the SCSI drive out and just go with the two EDI drives and reload WIndows XP. XP went through it's set up process and when it was done the computer restarted and the two drives don't show up and I get a disc read error press ctl alt del to restart...when I do that I get the same result.

I'm at a loss on what I'm doing wrong.