Hust picked up an old Roland EP-7 for free from a friend. They were throwing it out, because a few of the keys are finicky. I figured I could fix them, and then proceed to learn to play piano on it. The 4-5 keys that have trouble are all black keys. You have to hit them really hard to get the slightest sound. I'm assuming dirty contacts on the key switches/sensors. Is this probably a correct diagnoses? How difficult a repair would this be?

Thanks
Joe

I don't have any knowledge of the EP-7 but Roland does have pretty good service manuals for their keyboards - I bought the manual for the FP-8 - has the mechanical & assembly diagrams & part numbers for the keyboard/hammers - also the electronic schematics & layout & interconnects. It cost me $10 - saved me lots of time and $$$. Call Roland customer service in California - see their website. Good luck.