I bought my ES7 used, so there's no warranty. At a recent gig, the low F occasionally didn't sound when I played it. It's intermittent -- sometimes it works, sometimes it doesn't.

I had a recent job playing for a wedding under a tent on a dirt road, and the amount of dust that got on everything was quite astonishing. I don't know if that's what the problem is, but it could be. I'm thinking that opening the piano and using rags, Q-tips, and compressed air to clean whatever I see may be a good first step.

Back when I owned a Roland RD-200 I used to open it all the time to replace bad contacts -- it was even designed with hinges to make this pretty easy. Has anyone taken their ES7 apart? Is it straight-forward? Something you can do with a power screwdriver? Or should I take this to a professional? I don't see any evidence on the 'net of anyone ever doing this to this particular keyboard, so I'm a little reluctant to start.