Pianotech

Hey gang,

I find myself being asked to troubleshoot and repair an ailing Yamaha Disklavier MX-100.  This thing is a dinosaur, it has a 3.5" floppy disk drive.  I don't think the students have ever seen a 3.5" disk in their lives so they would probably connect their laptops to it and do whatever it is they do, but there's one or two notes that don't work on playback.  The acoustic piano stuff is all totally functional and the solenoids are all intact, so it's got to be some sort of circuit board malfunction.  Several years ago I honestly tried to get it to work, working with Yamaha and swapping out various boards, but to no avail.  Is this hopeless?  Should I just accept that whatever state it's in is the state that it's going to be in?  

Thanks!

Zeno

The MX-100 is, indeed, an ancient system. Have you actually talked to Yamaha tech support about this new problem? ( 800-854-1569 ) 

If it's just a couple of random notes it could be something as easy as pulling out the keys and cleaning the LED light path and physical gate on the end of the key stick. I've found all kinds of debris in there. In schools, most notably guitar picks. 

If, on the other hand, all the notes that don't play are the same note, like only A or only C notes, then it could be a dead or dying LED. The LED array is simply a 12 note sensing system. One for each of the 12 notes in an octave. The system scans all the keys in the piano but it does so with an array of only 12 LED's. If one of those LED's starts to fail, say the one assigned to note A, then all the A notes would show similar behavior. Last time I had to deal with this, more than a couple of years ago, Yamaha no longer stocked the module that held those 12 LED's and wound up sending me a handful of replacement LED's that I had to solder in. 

The unfortunate built-in problem with all electronic reproducing piano systems is that the electronics will wear out, and replacement parts will become unavailable, years before the piano starts to have problems. Fortunately the DKV is benign as far as how it affects the actual playing and performance of the piano itself. Since Disklavier's are "born" in the factory you can't simply upgrade. If the reproducing capabilities are important to keep available you will eventually need to remove the DKV and install a 3rd party system. Something like a PianoDisc.