The others, not sure. I have three Amiga monitors 1084 and 1942. Two have off colored displays which goes away when pushing on cable in back.
Seems like another resolder doesn't it? of course I know there are dangers with opening these without discharging. I need to learn and not the hard way.
True story. I was modifying a 1084 back in the day when they were new - I was putting a touch-screen overlay on it. It involved some internal surgery, mostly to put a secondary power supply inside for the overlay.
So, I'm sitting at my kitchen table, and I reach over the open monitor to grab a tool. And my bare arm touches the tops of some of the big cap cans.
The jolt caused my arm to swing back so violently that it lifted me out of the chair and back. I woke up looking up at the ceiling, and counted myself very, very lucky.
So yes, learn from my experience.