How do I know if my mouse wheel is failing?
A very common hardware problem in mice (even the most expensive Gaming models) is the "Scroll Jumping". This happens when you turn the wheel down and the page suddenly jumps up for a fraction of a second.
You can use this test by gently sliding the wheel in one direction; if you see that the "Current Address" flashes and changes unexpectedly, it is likely that your mouse wheel sensor (encoder) is dirty or damaged.
Infinite scroll wheels (Freescroll)
If your mouse has a "Freescroll" function (like some Logitech G502 or MX Master), you can press the release button on the wheel, give it a hard spin, and see how many thousands of pixels per second it can record before stopping.