17 R3 Keyboard producing random results

Hello all. I have a pretty major problem. Most of my keys on the keyboard are totally misbehaving. For instance pressing "p" might result in "[9a". Seemingly random. As if each key is being randomly remapped to various other keys or groups of keys.

All was fine until recently when I replaced my screen. Re-assembled unit and it fired up no problem, even let me input my password. I seemed fine for a few minutes then keys just starting going nuts as described above. Shut it all down, went to bed, woke up next morning and took apart again and re-assembled. This time it worked for a couple hours. I was so happy. But eventually they went crazy again and now ps i tylpa.e ths 9o3bvi9o7sylyl th.e ke.ys [d9o4nt \w9ork (translation: as I type this obviously the keys don't work.) 

I am now typing on a external keyboard, which today seems to be working fine but yesterday even my external keyboard was randomly producing "caps" as if the shift key was being pressed.

So I have been all over google and these forums and have found mention of keyboard issues but none quite like mine and no real solutions to be had other than send it in to dell, which I am reluctant to do since I am afraid of the cost.

Has anyone else come across this? Did you ever find a solution that worked? I have a growing pile of work to complete and I am sort of at a stand still. Any help would be deeply appreciated.