Amiga 2000 blurry screen

[Zac67]

Very weird - I'd have expected a grounding problem, but that would only smudge the output horizontally, not vertically.
Are you sure that the monitor is AOK?
Have you tested the exact same input to be good?
Is the output stable or maybe jittering (very fast)?

[Zac67]

With a non-Amiga PSU you'll need to set J300 to 2-3 (A500 tick/_VSYNC).

[Zac67]

@Roger
J300 determines where the _TICK signal for one the CIA clocks comes from. Usually it's derived from mains frequency (thru the PSU), on the A500/1000 they use the video's vertical sync which is cheaper - but with ECS you can change the vertical frequency which will make the clock unreliable. If you don't use 'custom' video modes, it shouldn't matter.