Korg Poly800/EX800 Users

Ok, I'm now scared.
I've had my MK-1 for a little less then a year now, and since day one I've
used a 1 amp 9v psu that I had been using with my CZ-1000. It still works
fine and I've abused it quite heavily.

Check your polarities... were they opposite on the keyboard and psu? And what
kind of amperage was the original psu supposed to have, as I never had one
in the first place...