Thanks for all the tips, I am moving forward guided by recommendations here.
The fear here is that I may be quite dangerous especially to Amigas.
I want to start simple, a power light on my 1200 doesn't work except when applying some pressure. Seems even to me a simple resolder.
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.