Mouse Wheel Test

The mouse wheel is one of the most frequently used elements of a computer mouse. We constantly scroll through pages, zoom in on maps, and flip through documents. But what should you do if the wheel starts malfunctioning: the scrolling becomes jerky, doesn’t register on the first try, or the direction gets mixed up? For a quick diagnosis, take this test with clear graphical feedback.

How to Use the Test?

• Hover your cursor over the black field.
• Start rotating the mouse wheel up or down.
• Observe the line:
  • Green color and upward movement = the wheel is scrolling down.
  • Red color and downward movement = the wheel is scrolling up.
• When the line reaches the right edge, the screen dims slightly (leaving a trace of the previous pass), and the line starts a new cycle from the left.

A perfectly functioning wheel, when continuously rotated in one direction, should produce a uniform line color throughout. If you are scrolling down (green line), no red segments should appear on the screen.

The appearance of the other color indicates “contact bounce” — micro-oscillations that are interpreted as rotation in the opposite direction. This often happens due to dirt in the encoder or wear and tear on the mechanism. The test allows you to instantly notice these artifacts.