Well I be damned, first time I hear about new PCs being 'broken'. Bad matching also sounds like pretty big exaggeration. Sure, many sets often weaker/worse components in comparison to the rest but rarely they are hardware breaking.
No idea how you came with 'my theory'. Only thing I meant is that there might be more than one thing which require replacement.
Most importantly, I forgot that Jers does not care about newer gaming titles, which means he does not need to upgrade everything to meet requirements to run them.
Nope, and yes I am gonna tell that it is from my personal experience and from people I met in school, university and work. Not reliable for you? Well too bad, I don't care : )
Still, would be nice to see the source of these "broken modern PCs". Might be even interesting.
And back to main topic. Only tip I give is pretty much the same what Xenalite already gave. There are professionals for a reason. Sure he can learn how to do it himself. Too bad it costs both time and effort. And if you **** it up, it's on you only.
As ranger said, life is short as it is. It's not worth it to overcomplicate it.