[sdiy] J-Wire Woes

[doof]

Hello all,

I have an old Sequential Circuits Pro-One that I'm trying to whip back into shape.  I've cleaned it up, fixed a broken black key, replaced and replaced all the brushings.  I'm pretty proud of the way it looks-- and it sounds even better.  Yet not all is perfect...  

The problem I'm having is with the J-wire keyboard.  Five of my keys don't work.  

The keys are (from left to right): The 1st 'D#', 1st 'B', 2nd 'G', 3rd 'D#', 3rd 'B'.  All of the j-wires make contact.  

At first I thought the offending wires might just be dirty, so I gave all of them a q-tip - isopropyl rubdown.  This didn't do anything.

Next, I generously sprayed Deoxit on the wires and the contact bar to the point that the wires were basically dripping red fluid. (overkill, I know-- but those spay nozzles aren't easy to control).  
I powered her up and amazingly all the keys worked perfectly.  Problem solved, I thought...  The next day the problem had returned-- same keys, no sound.  I guess the fluid had dried on whatever needed it most.

Still thinking it was the j-wires I bought some, clipped the old ones off, and soldered new ones in place.  That was this morning.  Needless to say, the problem is still there with fresh j-wires.

Then I saw the pattern.  Counting from the first bad key, every eighth key has a problem. Offending keys are exactly 2 octaves apart.  This pattern should tell me something, but I'm not sure what.  Perhaps a bad pin on the ribbon connecting the keyboard to the main pcb?  But why would the Deoxit have worked, if ever so briefly?

Is anyone out there with a familiarity of pro-one keyboard circuitry or j-wire keyboards in general?  I'm slowly teaching myself electronics so I do have a cheap Radio Shack multimeter at my disposal.  I would appreciate any help/suggestions/ideas in this matter.

Thanks.

-Tom
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