MSI is difficult as they do not provide any servicing details to the public and expect you to service it through an MSI authorized shop. Have you already taken all of the screws out of the back and separated the palm rest from the bottom panel? Gaming laptops tend to be a little misleading, with things such as hidden screws, or something that slides in a clip weird. Also, it's common to have a skeleton that everything attaches to from both sides as well as a palm rest and bottom panel.

Here’s what he is saying. if you replace one now. then one will follow shortly after as they have both been in the machine for the same amount of time. One for GPU aka the graphics, One for CPU aka brain . the fans speed are controlled by temps. One will always be a bit hotter than the other. so naturally they wont go out at the same time. they are trying to save you some trouble since you already need 1 and fans are fairly cheap. It’s the same in a car. if the driver window motor goes out, then you can expect the passenger window to go in 2-4 months.

The Home key was replaced and still doesn't work and built-in soft key doesn't work? Could try backing up all your phones data, then reset the phone. Also, those Cables can be really flimsy, plus im not sure of this one but now a lot of home buttons with touch ID are paired to that phones motherboard, and a new button would have to be reprogrammed. Other than that, You could try putting a different rom or atleast launcher on the phone, a lot of free launcher will offer a way to reprogram main functions with their Icons,docks, and widgets if you're okay with ads they are free too. Also worth considering dead spots on the bottom of the screen.