So, my friend noticed her laptop was getting a bit hot and slow. Naturally, she decided to give it a thorough cleaning without asking anyone for advice, or watching a tutorial on Youtube or whatever.
She opened it up, saw the gray paste on the CPU and thought it was a dust accumulation.
She completely scraped off all the thermal paste, thinking she was making it clean. To top it off, she used a dash of acetone to "fully clean it".
She put it all back together, tried to boot it up, and was genuinely surprised when it instantly became a brick.
The laptop is now deceased.
Lessons were learned the hard way.
Edit : It wasn't pure acetone in her nail polish remover. We had a good laugh after the fact and when I explained it to her, and she actively read this post with a big smile on her face ! She now "understands why the screws were hidden so well".