Yamaha CP80 has very distorted output - where do I start?

[Posegate]

I've had trouble finding an answer on this one. My Yahama CP80 piano (portable, electronic grand piano) was working great. It it's a real piano with pickups and High Z and Low Z outputs (xlr and 1/4" for each). Now it barely puts out a signal. What signal it does put out is distorted.

I don't know where to begin troubleshooting this problem - I'm just not experienced enough with these things.

What's your advice?

[Enzo]

How about start with a schematic?

[Posegate]

I found this from the manual: https://photos.app.goo.gl/Djoqg93b9oPZdW3XA

I can get photos of the circuit boards as well.

[Leo_Gnardo]

Have you had a look at the circuit board? The one and only time I had to repair a CP80, or CP70 for that matter, there was a big crack in the board. Fixed the problem by jumpering across the crack with individual wires, also applied a streak of cyanoacrylate (krazy) glue into the crevice to restore mechanical stability. Strange thing, prior to repair the piano produced output in spite of the crack but it was distorted. Worth a look.

If the board is OK I'd start suspecting any and every electrolytic cap. These pianos are getting old, and the 'lytics don't age gracefully.

[Jazz P Bass]

Here is the schematic: CP 80.zip

[Posegate]

Thank you! So... Now what? I'm pitifully novice at this.

[Posegate]

Thanks for the help with the schematic. I was able to bypass the power electronic modules and go direct from the electropiezo pickups to the output jack. Now I can use the amplifier without powering the instrument directly.

The downside is that I no longer have the tremolo or preamp eq available. Troubleshooting that is my next big task. Is the best way to approach this continuity testing?

[Posegate]

Sorry for late response. I've been trying to reply via my phone, and it hasn't worked. Thanks for the schematics. I was able to bypass the electronics and send the powered electronics and go direct from the pickups to the jacks. Now I can use my amp and it's clean. It sounds great, but I do miss the tremolo effect. Do I start checking for continuity next??