Hi, today I was using my Asus TUF F15—it’s not very heavy—and I was watching YouTube with it on my lap when suddenly I heard a crunching sound....

...I turned it off, opened it up, and saw that one of the fans isn’t spinning freely; it’s not completely stuck, but it doesn’t move as freely as the other one. I’ve already cleaned it carefully, but the problem persists… What could it be?