RD-700 uneven loudness

[olstad]

There are a couple of octaves toward the low end of my keyboard where the loudness is uneven, and much less than the other keys. It's worse when it hasn't been played for a while, but improves after playing for half an hour or so. At its worst, it's hard to make the keys sound at all. Maybe the contacts need cleaning? I've never had it worked on.

[bgiles]

As it's most noticeable after not being played for a while, I can only imagine this is due to the build up of something, like moisture, on the mechanism.
Have you considered covering it with a cotton cloth to absorb any resident moisture, and then plastic cover when leaving it for periods, this would help you identify the source of the problem.