Sony Vaio Keyboard

Hi,
I am having a problem with my keyboard on my Sony Vaio PCG-FX801 notebook. The keyboard suddenly stopped working. None of the keys are working. I opened the notebook and unscrewed the keyboard. When the keyboard is NOT touching the metal parts of the notebook, they keyboard works normally. However when I screw the keyboard back on, it will not work again, because it is touching the metal parts. Can somebody tell me how to repair this probably. I am assuming the keyboard has to touch the metal parts, especially because there are copper-colored tapes in on differen components, leadign me to think, that it is done for a reason.

Thanks.

You mean the flat green cord? What should I check? It looks fine (with layman's eyes), I detached and re-attached it. My notebook is still open now. When I lift the keyboard so that the metal part of the keyboard is not touching any metal parts on the notebook, it works fine. When I put it back so that the metal parts touch, it does not work.