Hi, wonder if anyone can help with a problem on my ES8? It’s 5 years old, been gigged hard, and has had no problems up to now except lately the D next to middle C has started to randomly generating MIDI velocity 127 however hard you press the key. As you can imagine, this is a right pain in quiet stuff and solo settings.

Some days the problem isn’t there at all, other times it’s almost every time I play the D. I find that repeatedly pressing the D as fast as I can can make the problem go away, which kind of points to a mechanical problem.

I have opened the unit up and removed the keys around the problem D and tried to work out what has gone wrong. I’m guessing it might be dirt or something in the velocity-sensing mechanism. I tried blasting with compressed air, but everything I do makes no difference.

Any tips appreciated, or does it need looking at by Yamaha service?

That sounds bad: the logic under the key is probably not apart
per key.
It looks like an entire bed replacement, unless they can clean it up.

;JOOP!

hi Paul-

Had a similar problem on my ES6 a while back. I took it to an authorized shop for repair and they went back/forth with Japan tech support for a while until they figured out it turned out to be a bad scanning diode under the keybed which affected the velocity sensitivity. I ended up replacing the entire keybed PCB (around $100 + labor).

However, on mine it wasnt just one note that was the problem. It would happen in a range of notes at random like every 4th or 5th note i think. See if you can find my old posts.

If yours is just the D, and youre handy with a soldering iron, you may be able to locate & replace the zener diode for that key. It is likely a .99 cent part at Radio Shack or your local electronics store.

Lastly, since your problem seems to go away when you actuate the key, before I did anything I would definitely try cleaning the electrical contact with a swab & alcohol first. You can also use a pencil eraser to clean the metal part. It could just be a dirty contact!

Good luck!

Rich

Rich,

Thanks for the info - that’s really useful. I got as far as opening the case and taking the ‘D’ and surrounding keys out, but stopped there. I will be a bit more adventurous next time and see if I can expose the mechanism.

Paul