SCROLL WHEEL REVERSE-JUMP TEST

Run a repeatable scroll wheel test

1. Choose TEST SCROLL DOWN, keep the pointer inside the capture area and rotate only downward until at least 20 browser events are recorded.
2. Write down total events, opposite events, opposite rate, median delta, median interval and delta mode.
3. Reset and repeat the same direction two more times. An isolated event that does not repeat is weaker evidence than a recurring pattern.
4. Run three matching trials upward. Compare direction rather than mixing up/down movement in one sample.
5. If the symptom repeats, change one variable: another USB port or receiver position, wired mode, browser, operating system or computer.

Interpret the direction sample

PASS means the uninterrupted sample reached 20 browser events without an opposite-direction event. It does not certify the encoder or prove that no event was missed.

WARNING means one opposite event occurred, unsupported input was ignored, or the session was interrupted. Reset and repeat before drawing a conclusion.

FAIL means at least two browser events opposed the selected physical direction in one uninterrupted sample. Repetition across trials and environments is stronger fault evidence.

Worked browser-event examples

• 0 of 24 opposite: this run passes. Repeat twice because an intermittent wheel can behave normally for one sample.
• 1 of 24 opposite: warning only. Reset, repeat the same direction, then compare the other direction.
• 4 of 24 opposite: the run fails because repeated reverse-direction events were observed. Confirm that physical motion stayed one-way.
• 0 of 24 but a felt notch did nothing: the page cannot count an event the system never delivered; note the physical skip separately.

Troubleshoot reverse scrolling

• Confirm the pointer remained inside the capture area and that you did not reverse direction while stopping.
• Disable vendor smooth-scrolling or remapping temporarily, then repeat with the same settings documented.
• Reconnect the mouse, try a direct USB port, move a wireless receiver closer and charge or replace the battery.
• Compare another browser. A browser-only result points toward software handling; a symptom that follows the mouse is stronger device evidence.
• Test another computer before cleaning, opening or replacing hardware. Follow manufacturer instructions and warranty terms.

Limits of browser wheel testing

Browsers expose wheel events, not raw rotary-encoder transitions or certified physical detents. One detent can produce one or many events, and smooth wheels or trackpads can add inertia.

The page cannot detect a physical notch when the operating system sends no event. Delta magnitude also changes with deltaMode, browser, driver, operating-system settings and vendor software, so raw values are not a universal wheel-quality score.

Privacy and result scope

Wheel-event counts, intervals, deltas and classifications are calculated in this page and cleared by reset or reload. This tool does not upload the diagnostic sample. GearCheck Lab still serves normal site resources and may use consented analytics under the Privacy policy.

The result describes browser-visible input from one session. It cannot inspect the encoder, firmware, receiver or USB polling directly.

When another mouse test is better

Use the Full Mouse Test when the symptom is unclear, the Double-Click Test for unintended repeated presses, the Hold & Drag Test for held-button dropouts, the Polling Rate Test for comparative movement cadence, and the Mouse DPI Estimator for measured travel comparisons.

Scroll wheel test FAQ