Might be a dodgy micro switch? Replace or swap with another to see if problem moves. Otherwise check for continuity for ground on it and then between micros terminal and jamma connector.
Found it, it was the block connector.
It's some awful cheap thing which doesn't have a lock the other end and the wires are loose and popping out all over the place haha. I've done my best with it for now and its working but the entire block is going to need rewiring eventually.
For the Colours it looks like you have white so they are all firing, there should be colour test bars on the 60in1 test menu, its a while since I had one but think there will be a chequer with RGB and white and should possibly be also one showing all the separate colours and white ramping up fully off to on so you can see if some cutting out early.
Could also be that the video on the 60in1 isnt perfect.
EDIT: Looks like test screen is only the full Red, Green, Blue and White squares, and doesnt have a graduated output for each colour to see if one is cutting out early.
Here's the basic RGB pattern in the 60 in 1.
It seems ok i think? But something does look off in person I'm not sure what it is. I'm going to fire up my Cosmic Avenger PCB shortly and see if that is ok. Like you said it's highly likely the 60 in 1 is off not the screen.
EDIT: I've turned the brightness up ever so slightly and it looks amazing now! Was just a little low.
Can anyone tell me what the hell this is?
I think it's got something to do with the RGB signal? Not 100% sure? But whatever it is, i tried the switches and as i had my hand on the block i must have touched the screws which must some how be live because good god did it give me a shock haha!
It goes to the neck of the CRT from the chassis through that little box.
