Ensoniq ASR-10 (Keyboard test failure on boot)

I am repairing an Ensoniq ASR-10 keyboard. It would not boot due to a keyboard test failed (also the enter/yes button is not working so it would not finish booting. I have buttons on order so I think I can fix that part.

As for the keyboard failure. I have read that the most common causes would be:

  1. fuses 3 or 4 - (mine do not appear to be blown)
    2)poorly connected or damaged ribbon cable from keyboard to main board (when i opened the cases the ribbon cable looked like it was connected well. I have not replaced it yet.
    3)the two halves of the keyboard have a poor connection. This is the one I am worried about. I have taken everything off the board except the keybed itself. Before I open that can of worms do any of you know of a video or site that describes the repair for this (which i think is hard wiring the two halves together)?

I appreciate any thoughts. I have done alot of searches for repair info and i have the service manual but it does not get into that repair that i can see. Also, youtube hasnt yielded a good how to for this specific item.