> because a lot manufacturers don’t want anyone to know how to fix them.

I actually don't think they could care less if you fix it yourself. Apple, Samsung etc have done nothing to stop repair shops around the world that fix/replace phone or computer components and companies like MacSales have happily existed for years.

I can imagine if he has attempted to repair a MagSafe charger or a battery that Apple would rightly want to protect their customers but anything else would be largely harmless.