Off topic but this post will attract Kinesis users... Does anyone know how to deal with ghosting on the Kinesis Advantage?I bought a used one but quite often it repeats the letters that I press and that's not how it's supposed to work. I haven't used it in years but it would be interesting to fix it. I know it's possible to change the controller, but how do I know if that is the issue?

Do you mean 'chattering'? Double presses can happen with electrical contact mechanism switches, particularly if they are old or dirty.

If I press 'f' it can come out as 'ffffff'. They're not dirty, but they're probably 10-15 years old. I assume this is much harder to fix than changing the keyboard controller.