Hi everyone,
I’m reaching out for help or advice regarding my Korg SP-280 digital piano, which has been behaving strangely.
The Main Problem:
- The keyboard randomly turns off while I’m playing.
- Sometimes, it doesn’t turn on at all even after being plugged in for hours.
- But then, unexpectedly, it turns back on after several hours or even the next day.
- The power LED is off during these episodes, and none of the keys respond.
Strange Observation:
- Even when the piano appears completely off, if I connect a stereo jack from my laptop’s audio output, the sound from my laptop plays through the keyboard’s speakers.
- However, the piano itself still doesn’t function, and the power light remains off.
What’s Been Done So Far:
- I had the mainboard replaced a month ago (cost around $120).
- The issue disappeared briefly, but now the same problem has returned.
- My technician recently opened it again and found some leftover solder residue, cleaned it, and the piano worked… for a while.
- But now, it’s randomly shutting off again, sometimes not turning on for hours.
Temperature Notes:
- Sometimes it works after being off for a while (as if it needs to “rest”), but other times it won’t turn on even when cold.
- I’m wondering if it could be a temperature-sensitive component, a power supply issue, or a faulty capacitor?
My Questions:
- Has anyone experienced anything similar with the Korg SP-280 or similar models?
- What components should I or my technician check again?
- Could it still be related to the mainboard or capacitors, even after recent replacement?
- Any suggestions for further troubleshooting?
I’d really appreciate your thoughts or insights. This piano is very dear to me, and I use it for both practice and teaching, so I hope I can find a reliable fix. 
Thanks in advance!