CF-18DHAZXKM, hard drive/cable issue

I recently purchased two CF-18DHAZXKM toughbooks.

Now, one of them was constantly in use and never had issues. The other kicked around a car dealer and then someone's garage for about the last 2 years.

When I got them in my hands and loaded them up with the WinXP and got it up to speed with SP3 and the other updates from MS, all was good with the one with more use. The "kicker" as I'll call it was giving the blue screen of death randomly and somewhat often.

I swapped the hard drives between the two, caddy assembly in/out between them, and the blue screen of death followed the caddy from the kicker. BSD's in the same manner now but of course in the more used CF-18.

So then I swapped out the hard drive for a known good unit from an old T-40 I had. Ironically both hard drives were EXACTLY the same: HITACHI Travelstar 40GB. Both were also manufactured in the same year, 2004.
However, upon reinstall of the known good drive, instead of trying to boot, it does nothing. It runs thru the bios/post screen fine and then blank.
I pop in the original hard drive: same result now, no boot.

So I figure its the cable.
I order two (just in case the same thing happens to the other one) OEM cables from Heartland.
They arrive.
I install the new cable.
SAME RESULT: NO BOOT.
Now, time for something different: A brand new Transcend 16GB SSD SLC drive.
SAME RESULT!!
Now, I have two PERFECT CF-29N's (one of them I'm posting from right now!), so I install the SSD into it...actually, this very one I'm posting from...and I get Win2k installed NO PROBLEM and it boots fine and dandy.

Now, swap drives back and I'm up and running like normal and nothing happened on the CF-29.

The SSD back into the CF-18...partial boot. It starts to load Win2k but freezes while its on the black screen with the "Starting Windows" and the left to right indication bar.

I try to boot from CD and re-install Win2k: BOOTABLE DEVICE NOT DETECTED.

Ok, so I swap the OLD cable back in: Same results.

Ok, swap the caddys back between the two CF-18's...the more used one boots fine on BOTH CF-18's.
The kicker's caddy just black screens with both CF-18's no matter which one of the 3 drives are in it.

Then I took apart the known good caddy from the more used CF-18 to compare with the install job of the other 3 drives in the kicker's caddy: IDENTICAL.

Still wont work.

I'm at a loss.

Any ideas?

Thanks...