This is what happens when you don't clean your G502 for nearly 4 years : r/G502MasterRace
Logitech G502 Lightspeed Gaming Mouse
scrolling - Why does my Logitech mouse sometimes ignore the scroll wheel turning? - Super User
How to Fix a Sticky Scroll Wheel on a Logitech Mouse - groovyPost
So I got a sweet mouse from a friend for free, only problem is... it's nasty! Any tips on how I can efficiently clean it without damaging it? (Logitech G502) : r/MouseReview