Clavinova CSP-170 Issues

I have multiple issues on my piano.

First, when you plug it in the piano automatically starts up. You can then shut it off with the power button but it will not power back up with it. To turn it back on you need to replug it into the wall, pressing the power button only makes the power light brighten but does not turn it on.

I could live with that, but now the piano is not playing piano sounds anymore. It makes this awful distortion/static sound, no more piano sounds. You will occasionally hear a key or two under the distortion but never a clear key sound alone.

This happens with headphones and over the speakers both.

I have looked at the capacitors on all boards inside and did not see anything leaking or bulging, fuses are fine as well. Super frustrating.

Not an easy piece to work on … got a very complicated 2-stage SMPS in it. Your issue could be bad voltage from the 2nd SMPS or a bad DM board.

Power on/off is done via a single contact that is being checked by the 2nd SMPS secondary stage for power on and the DM board for power off.

I suggest to get a YAMAHA Service Tech to look at it. - that SMPS is dangerous - carries 340V if you are in 220VAC country.

I’ve tried to get several to look at it and have only found one in my area and they have a 6 week turnaround for providing just the diagnosis. I have soldiering experience, I just need to know what I should try to replace, getting a Yamaha service manual is also impossible it seems.