Korg SP250 Portable 88 Key Digital Piano With Keyboard Stand Bundle & Bench Headphones 10ft Qtr Qtr Instrument Cable - Answered Questions & Fixed issues

http://i.korg.com/SupportPage.aspx?productid=134 UU

Question edited for clarity. It is a known issue, you need an electronics engineer. https://www.google.com/search?q=korg+m1+distorted+output ..

No one knows the fuse type, but the details should be on the fuse itself. Then you can't get them from an electronics store or Amazon. The Service Manual is in the link. https://www.google.com/search?q=Korg+n364+keyboard+replacement+fuse ..

See page 166 troubleshooting of user manual. It may help. 331ad6cf40f982ddcfbb201db1a6d34f.pdf (korg.com)

If you contact Korg, they can send you a dowloadable link to burn the software to a disc.

up to you if you ant to spend the money to have it diagnosed and repaired

$213 or take to an electronics service technician to diagnose which part got damaged and replace the component/s. https://reverb.com/au/item/69569832-korg-n364-n264-x2-x3-workstation-power-supply-board-assembly-part-klm-1633 https://www.google.com/search?q=Power+supply+board+of+Korg+X2 ..

Sounds like loss of memory\programming.Go to Korg website for download.

https://www.google.com/search?q=install+firmware+in+Korg+X50 ..

It is a known issue! https://www.google.com/search?q=display+problems+with+KORG+D1200 ..

Give your email, I'll send for free.

The buttons are damaged or defective. Replacement may be the only answer.

Might be a case of opening up the M50 as the previous poster did and wiggle connectors and components until the sound is affected. If you have some electronics experience, it should be fairly easy to figure out which board to investigate.

Right away or after it's been working awhile? Try coolant spray on power supply components.

Try resetting the software.

Maybe because the battery needs to be replaced.