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"Beautiful housing, all buttons intact - HOWEVER - was many many years unused and some combination of mechanics and electronics are now poor/unusable. Oscillators seem to work but feeble at best, there's a stuck-'on' key and there will need to be some serious diagnostics and repairs done to key triggers, pots and switches I assume, to get back to reliable playing quality."
If it's a j-wire version, the wires likely just need cleaning and bending. I once picked up a Pro-One from Guitar Center for $125 due to a stuck note. I opened it up, bent the j-wire back and it was as good as new. They way the keyboard works is there is a little wire that extends from them. When you press a key it tilts up and makes contact with a metal bar. If the wire is bent it can end up touching the bar producing a stuck note. If the wires and bar are oxidized or dirty for whatever reason, pressing notes can sound unstable. That said, if you pick this one up and it's not due to these issues do not blame me. :) Just throwing this out there for Pro-One owners with similar problems.
