Similar problem with a monitor
About 25 years ago I got a shiny new colour mopednitor. Nothing fancy - probably about 16". Anyway, it was flakey, and frequently didn't work. Amazingly, it had an on-site repair warranty. I'd never seen one of these before, so thought I'd give it a go, and called out an engineer.
He arrived, put his hand behind the monitor, wiggled the power cable a bit, and it sprang to life. I've never been so embarrased. It turned out that the pre-IEC power cable didn't have a particularly good fit; he said it happened a lot.
Back to crappy forums - when you get as old as me you find there's another problem. You have an incredibly complicated problem, find a years-old thread somewhere, get to the end if it, and discover that the person who posted the solution was... you. Happened a couple of times to me.