Unusual Korg 01/W issue

[sargfowler]

Does this post sound like a similar problem?

Korg M1 - Screeching, echo on output

I’ve got a Korg M1 that needs some love. I’ve changed the coin cell battery as it was 3.0v for a new one. The power rails are OK at 5v and +/- 11.8v. I’ve uploaded the midi file via sysex librarian and get the correct names for the presets. I changed the buffer settings to 256. However, the sounds are really distorted with screeching, ring and echo. It’s as though all the effects have all been switched on. I went into the settings and turned all the effects off and get a reasonably clean sou…