I have a ~20 year old S80 that I've used pretty heavily over the last two decades. I've put this off for a long time, but the action/velocity across the keyboard is definitely worn and uneven.
What's the best way to get this repaired? Can I clean it myself and will that do enough, or should I take it in for repair and possible replacement of parts? I've opened it up myself many times and am comfortable/familiar with the components.