Korg Delta pitch issues

Hi all!

I am not very versed in electronics repair. I’ve been playing an older Korg Delta for a couple years. Haven’t had any real issues. It could probably use a little more cleaning, but it’s been consistent. Recently, the tuning has become weirdly inconsistent. It will intermittently go out of tune by 1/4 to 1/2 step, and then often kind of corrects itself after a few seconds. Does anyone know what causes that? I’d love to try my hand at fixing the issue. It’s such a fun instrument.

Best,

Luke

Possibly an issue with the pitch bender.
See if the pitch comes back when you tap on the pitch bender.

You nailed it. I turned off the FM depth in the joystick control section, and the issue seemed to go away. Bends also seemed a bit inconsistent / strange when using the joystick. I definitely think it’s something in that section of the instrument. At least it’s playable with that knowledge!

That’s what my synth is doing. Just need to figure out how to get inside.