To give a better explanation for op and to make sure we are on the same page:
circled in red are the screws i am talking about. From what i understand from your post only two out of those four screws are installed. You
must make sure those screws are complete. That is the cause of your overheating.
i assume the “black thing” op is talking about are the ram chips, ive drawn yellow marks on those. They use thermal pads, not glue. I recommend replacing them with any thermal pad with the same thickness.
forgive the sloppy editing of the photo, i did this on my phone.