Yamaha PSR 400 won't power on properly, goes to Error

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Hello everyone, new member here. I have a Yamaha PSR 400 portable keyboard that no longer powers on properly. Either on a power adapter that I have used forever and new batteries. When I power it up it starts to spell out Error on the display. Interestingly, it spells it backwards several times then after several times of that shows Err. I can get it to come on semi- normal if I hold down the clear button while turning on the power. I can also hear a very slight sound of the speakers getting initial power, but if I touch any key or button that should produce sound, it goes to Error and then nothing. the keyboard has been setting unused for some time now and has gone through Hurricane Michael, but I don't think it got wet. The power jack on the back looked to me like it had some corrosion in it where the cord plugs in and I cleaned that up real well. I figured this would cure the problem, but figured wrong. Same issue. I also opened it up looking for any really obvious problems, but didn't find anything. Now I am at a loss for what to look for next. It really acts to me like it doesn't get power enough to do what it needs to be doing. The power adapters I use,( and have been using) are 12v and 1000 ma units. They both test well on multi-meters so I don't think the problem lies within them. Any help and advice would be greatly appreciated in getting this thing going again. Thank you in advance to all.
 

happyrat1

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Are your power supplies regulated or unregulated?

I've seen that type of behaviour when using unregulated supplies because the ripple current causes too much noise.
 
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I have two of these and one similar to them that I have used for as long as owning this keyboard. Never a problem before, but that doesn't mean they may not be now. It seems strange that it always worked perfectly before it sat for a good deal of time unused. Can you recommend a good regulated power supply for me to try on it? Appreciate the response.
 

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Good deal. I just pulled it up and they are very reasonable price wise too. Have one on the way now. Should be here Tuesday. Thank you for the help. Now I'll keep my fingers crossed that this fixes it.
 

happyrat1

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In the meanwhile don't plug it in anymore.

Power supplies often go bad with age and use.
 
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12/19/23 update. I got the new power supply in the mail today and tried it. No new results to report. Same results as with the other power supply. I went into the keyboard and found one disturbing problem. I saw this component on the main PC board. The brown stuff caught my eye at first and upon closer inspection, it appears to be glue added to the circuit board to help stabilize what seems to be a crystal oscillator, according to the symbol on the board underneath this glue. The numbers on this component and on the board are 9.4 mhz. I tried looking this up online to get another one, but the only thing I can come up with is 8.0, 10.0, 11.0 MHz and either side of these numbers. Not being an electronics wizard, I don't know if I have to have an exact match for this to work or not. What I did find on closer inspection was rust on the underside of the component toward the circuit board. Just barely touching this made it fall off the circuit board altogether. It appeared that rust ate the legs(s) of the component , possibly causing a short or an open circuit. I am wondering if this has shorted out other circuits as well or if there is just an open circuit and this is causing the problem of the keyboard not 'booting up' properly. I have attached pictures of this. Any ideas/ suggestions would be greatly appreciated.
 

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happyrat1

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It's probably not worth repairing at this point.

$50 would buy a replacement keyboard at a flea market.
 
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Yeah that's kind of what I was thinking. This one is actually old enough that it was made in Japan, not China like the ones you get nowadays when purchasing a new one. Thanks for your help in trying to get this one going again.
 

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