Charger, battery and overheating.

So I've got this old Asus ROG here, now I know that the battery needs to be replaced, as well, it was made in 2011!

When I plug it in, I gotta hold the charger at a certain angle, the angle changes each time, charging light will turn on, and then it turns on. After a few minutes though, it shuts off, after the first shut off, each period of getting it to work becomes shorter.

Example: First Session: 10 minutes. Second Session: 7 Minutes. Third Session: 4 Minutes. This resets after it hasn't been used for a couple hours.

Now I think I know why this is, the barrel jack of the charger and the charging port get very hot, quickly. Now, I've cleaned out the fans, but I still need to redo the 12 year old thermal paste that is probably non-existant at this point.

The keyboard is a mess, missing keys and all that.

I've since completely stripped the computer to give it the cleaning of it's life (12 years in a house with 2 cats and a dog and not a single cleaning!), it's currently still in pieces, but I can still plug the motherboard and screen in and get it to turn on and work.

Upon doing this, I discovered that one of the fans doesn't seem to want to work, unless perhaps, this is a feature.

Below you will find a video of me testing the fans, and discovering this very issue, I double checked all the connections too, 100% in place and connect, wires don't appear to be damaged either.