Amiga External Flicker Fixer on Amiga 4000?

[Acill]

I have one of these that was branded by Software Hut in the US as the Toastscan. You should have an adjustment screw on the side that needs to be turned. It has super fine threads as well. It will turn a lot of times before reaching one end or the other. I've got to tune mine quite often, but use an Indivision now on all my machines.

[Acill]

I do have one of the first, still packed into metal case by Eyetech. Changing it from my A500T to my A4000 did require lots of turns with that tuning screw. And when the box warmed it needed some tuning again.

This is also my experience with it.