I was going to post this in the discussion about DP actions, but I figured I'd just give it its own thread.
So, my beloved RD-1000's Eb4 key started sticking this past Sunday. Wasn't sure why, so I decided to investigate.
Here is the inside of the RD. 4 screws on each side underneath, and one screw on each end cap, near the front. Then the whole top lifts up. That part was easy. What isn't pictured here is the front felt rail, the metal lid that covers the contact board, and the keybed locking bar, as I had just taken those off.
Here, you can see the incredibly simple action. There are various pins along the back of the piano that some of the keys slot into. The culprit for the sticking Eb4 key was that the rear pin was rubbing right against the matching notch in the key. Solution: bend that rear pin to the center, ever so slightly.
While I had the piano open, I then decided to remove all of the keys, clean up any dust/debris in the bottom of the piano (there was a lot of it), then gently wipe down each key to get rid of any clumps of dust.)
Now, all that's left is to figure out why the right output is dead, (works fine with just the left/mono out), but since I'm not very good at soldering, I'll leave it alone for now.
After the cleaning, though, the piano plays a lot smoother than before.