Market Research Group

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 a new to this, and I don't know where to start. Other technicians don't have time to show me the ropes, so I'm reaching out here. Could anyone send me a YouTube tutorial? It would be better to see an example than to read about it. If you don't know of such a tutorial, could you tell me what to look for in the manual and on the power supply?