Very informative post 💩
If you have tried everything, that also includes any suggestion that ever may come up from anyone on any forum - because you've tried that too 🙄
Assuming that only one computer is part of your problem, then the only logically solution is to buy another one.
Ps : please be friendly to the environoment, instead of tossing the old computer on the bin, consider donationg it to someone or just sell it "as is" 😉