Fast way to check coin values at coin shows?
Going to my first coin show soon. Any fast way to check values while there?

Going to my first coin show soon. Any fast way to check values while there?
I repair TVs for a living, and right now, I'm trying to figure out the problem with the Samsung BN44-00522B power supply unit, as I suspect that's where the source of the problem lies. The TV often doesn't turn on the first try and turns itself off, every like, 5 minutes. Standard checks haven't helped. I found a detailed schematic with electrical specs, a parts list, and schematics on manualmachine.com. But I'm new to this stuff, and I don't know where to start. Other technicians don't have enough time to show me the ropes, so I'm reaching out here. Could anyone send me a YouTube tutorial? I think it would be better to see an example than to read about it. If you don't know of such a tutorial, but know something on topic, could you tell me what to look for in the manual and on the power supply?…