Be sure to add me to your favorites list Yamaha P-90 Digital Electronic Piano Original Overall Circuit Diagram Sheets in their cover. Great, original Yamaha set of overall circuit diagrams for the big P-90 model electronic digital piano keyboard. This is the large overall circuit diagrams, all tucked into an original Yamaha service envelope with holes on one side of it for placing it into a binder if you wanted to do so. Very lightly used and in near like new condition. The P90 is an expensive instrument, and these sheets would be a great investment if you need to repair one. These are original documents from Yamaha! This is a manual or document, this is NOT a piece of equipment or instrument. If you have any questions, I'm always happy to answer them. Thanks for looking and please check out my Store!