K8N Neo Platinum killed my X800 Pro

Question

I installed my new K8N Neo Platinum.
I had an existing BBA X800 Pro in my old Epox 8RDA which I moved to my new MB.
After firing up the K8N Neo, my X800 Pro was dead.  
The X800 Pro was fine just before I put it in the K8N Neo Platinum MB.
One can reasonably assume it was the K8N Neo that killed my X800 Pro - what else could kill it?
One thing that I did wrong was to not attach the smaller MB PSU plug (the 4 pin CPU power supply plug - I attached the other wider one), however, that should not kill the video card !!!
I thought the MB was dead because the CPU fan was not spinning but after attaching the power supply plug, the MB started and CPU fan was spinning, however, my beloved X800 Pro was dead.
I tried my X800 Pro in another computer and even reinstalled my old Epox MB, but to no avail. My X800 Pro is officiially dead.
I'll be sending a $400 bill to MSI for a replacement

Answer 1

I know it's dead because it says something like this on bootup:
YOUR VIDEO CARD POWER CABLE IS NOT CONNECTED, PLEASE RTFM
It didn't use those exact words but that was the meaning.
After that mesage, the computer will not continue with the boot process - it just sits there like big lump of expensive rock  
The power cable is connected to the video card so the message is erroneous.
I've tried the video card in another computer and the results are the same with the same message.
The video card is dead.
I closely examined the video card and I see no signs of damage. I paid close attention to the power supply socket on the video card and I could not see any damange and the soldering looks intact.
It might be simple to fix the video card but I wouldn't know how to do it.