Mid-2009 MacBook Pro sees internal SATA hard drive, but will not boot from or format

I inherited a Mid-2009 MacBook Pro (15-inch, 2.53 GHz model) with a very strange issue.

It first presented itself as not being able to boot from the internal SATA hard drive that came with the computer. Nothing I tried could get it to boot, so I assumed the file system was corrupted beyond repair and booted from a CD to try to format the drive. Disk Utility on the CD would not format the drive, giving me strange error messages like "Unable to write to the last block of the device".

At this point I figured the drive itself must be toast, so I pulled it out and put another known-good SATA hard drive in, booted from CD, and attempted to format. Again, same error messages and an unsuccesful format.

So I had the bright idea of formatting one of the drives in an external enclosure and then putting it in the MBP to see if OS X would even install. No dice. Get a cryptic error message before installation even begins.

So I installed OS X on the drive in the external enclosure and put it in the MBP, and it attempts to boot, but never goes anywhere.

So to sum up, the symptoms I'm seeing:

1. MacBook Pro CAN see internal SATA hard drives.
2. MacBook Pro WILL NOT boot from any internal SATA hard drive and cannot format or install OS X to any internal SATA hard drive.
3. MacBook Pro WILL boot from any CD or external device and seems to work properly otherwise.

At this point I'm thinking it's one of two things: the hard drive ribbon cable or the SATA controller on the logic board.

Since the MacBook Pro seems to work completely fine other than this one issue, and will boot properly from both external devices and the CD (also a SATA device), I'm thinking and hoping that it's just the hard drive ribbon cable. From my searches online, I've heard that this batch of MacBook Pros is known to have issues with the hard drive ribbon cable, but it seems in most cases this manifests itself by the Mac not being able to see a drive at all.

I've done quite a bit of troubleshooting to get to this point, but right now I'm just looking for any feedback at all. Specifically I'd love to know a way I can easily test to see whether it's the logic board or the cable.