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

Joined
Dec 17, 2023
Messages
5
Reaction score
1
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

Destroyer of Eardrums!!!
Joined
May 30, 2012
Messages
14,235
Reaction score
5,723
Location
GTA, Canada
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.
 
Joined
Dec 17, 2023
Messages
5
Reaction score
1
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.
 

Attachments

  • Untitled.jpg
    Untitled.jpg
    86.6 KB · Views: 8
Joined
Dec 17, 2023
Messages
5
Reaction score
1
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

Destroyer of Eardrums!!!
Joined
May 30, 2012
Messages
14,235
Reaction score
5,723
Location
GTA, Canada
In the meanwhile don't plug it in anymore.

Power supplies often go bad with age and use.
 
Joined
Dec 17, 2023
Messages
5
Reaction score
1
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.
 

Attachments

  • Screen Shot 2023-12-19 at 5.09.30 PM.png
    Screen Shot 2023-12-19 at 5.09.30 PM.png
    752.8 KB · Views: 12
  • Screen Shot 2023-12-19 at 5.09.57 PM.png
    Screen Shot 2023-12-19 at 5.09.57 PM.png
    783.2 KB · Views: 13
  • Screen Shot 2023-12-19 at 5.10.17 PM.png
    Screen Shot 2023-12-19 at 5.10.17 PM.png
    754 KB · Views: 12
  • Screen Shot 2023-12-19 at 5.10.41 PM.png
    Screen Shot 2023-12-19 at 5.10.41 PM.png
    753.9 KB · Views: 11

happyrat1

Destroyer of Eardrums!!!
Joined
May 30, 2012
Messages
14,235
Reaction score
5,723
Location
GTA, Canada
It's probably not worth repairing at this point.

$50 would buy a replacement keyboard at a flea market.
 
Joined
Dec 17, 2023
Messages
5
Reaction score
1
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.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

No members online now.

Forum statistics

Threads
14,400
Messages
89,674
Members
13,349
Latest member
jsfmedida

Latest Threads

Top