of reconditioning the conductive rubber strips
i.e. my aftertouch repair revelation :)
After I finished my first attempt at repairing the aftertouch feature, I was pretty disappointed with the results. The feature worked (whereas before the cleaning it was completely non-functional), but it still required that you put a TON of pressure on the keys to activate it.
I then decided to open it all back up and figure out what went wrong or see if there was anything else I could do to remedy the situation.
I ran some tests by having the keyboard powered on and touching the 2 aftertouch strips with a piece of metal to bridge the connection. To my surprise, it worked like a charm! Very distinct and very loud when the slider was all the way up and the 2 strips were shorted. So seeing the results of this small test, I turned my focus to the weak link in the chain; the conductive rubber.
Obviously, the rubber just wasn't making a good enough connection for the foil on top to short the 2 strips. So logically, I figured that I hadn't cleaned the strips well enough so I got out the alcohol & q-tips, then started cleaning again. It was taking FOREVER, and the q-tips were NOT getting to a point where they were coming clean(they just kept getting black).
It was then that I had the revelation.... rubbing the alcohol on the strips with the q-tip wasn't so much cleaning the strips as much as it was reconditioning them! The harder you rub, the blacker the strips become thus restoring the carbon conductive material to the surface of the strips. Sure, the oxidation on the gold strips and the foil contribute to the problem, but I believe that the heart of the aftertouch problem is the poor conductive rubber strips.
Well, at the rate it was going, it was going to take hours and hours to get each strip's conductivity back up to speed. Then I had a brainstorm: why not just restore the conductivity of the strips by coating them with graphite!? So that is what I did, I got out the old pencil sharpener and a solid lead pencil and started sharpening!
After I had a nice container of powder, I simply rubbed the powder into the surface of the strips. I RECOMMEND that you wear a rubber/vinyl glove for this procedure as you will turn your fingers black, and oils from your fingers may affect the graphite adhering to the strips. I decided to coat each side once, then wipe them with a tissue, and then repeat the process (I really wanted to make sure that the graphite was embedded into the strips!)
Now, I'm sure you can BUY some graphite lubricant or a kit to repair conductive rubber, but I used what I had on hand. I cannot attest to how long the graphite will hold up under normal usage, but I see no reason to believe that it shouldn't hold up considering the strips are sealed up really well when everything is back together. You can check out the pictures below for visual details.