I have a Yamaha synthesizer "S90" bought long time ago.
I haven't used it so long but recently I thought maybe I should give a try to use the old synth piano at home for fun.
When I power it on, it gives the error message below (the figures are not accurate as I copied and pasted it from somebody else's post who has had a similar issues as mine. )
It eventually disappears and the piano works if I turn it on and off several times or sometimes more than several times.
I called a Yamaha service center to see if what they can do with this discontinued model and they said it might be a capacitor issue (it is also known as a mainboard??). I am a layman in electronic devices so I won't know. But it would cost about $500 to get it fixed ... and they also said that it'd be better to bring it to the center when it still works otherwise there might nit even a troubleshooting if the machine doesn't get powered. I don't want to spend that much money on this old gadget but it is still a very good synthesizer so I was wondering if there is any way to get it fixed with less money spent.
A friend of mine told me that it might be a soldering issue on the capacitor, he might be able to help as he knows how to solder stuffs... but he also said it wouldn't work without a total replacement of the capacitor or main board if it isn't about soldering.
=== system down ===
error code 00000420
occurrence at 8c007620
content of SR 40000000