Start with the combination that matters
If three keys work alone but one disappears when you hold them together, compare that exact combination. A maximum counter alone cannot tell you which combinations work or whether the browser intercepted a shortcut.
Three terms, different observations
- Rollover
- The ability to report keys held together. “N-key rollover” is a broader device claim than any one browser combination can establish.
- Ghosting
- An unwanted key signal associated with a combination. Missing inputs are also commonly called ghosting in everyday searches, but a missing signal is a different observation.
- Blocking / missing input
- An expected key does not reach the page. The keyboard, an incomplete gesture, a shortcut or lost focus can produce this result.
Build a reproducible comparison
Select two to six keys
Choose a preset or a custom combination matching the task that causes trouble. Match the reference to your physical layout. Avoid operating-system commands; Tab and Escape remain exits.
Establish the isolated responses
Start the test, press and release each selected key alone. The guided check waits for this baseline before comparing simultaneous input. If a key is already missing alone, investigate it separately first.
Hold the whole selection, then release
Press the selected keys in order and keep them held together before releasing all of them. Compare the peak set with your intended combination. An interrupted attempt stays separate from completed attempts.
Reverse the order and compare elsewhere
Repeat in reverse order, with the same keys and connection. Then try the intended action in the affected application. Change only one condition, such as the connection or keyboard, before another comparison.
Example: A + S + D
Illustrative US-reference scenario, not a hardware measurement. A, S and D each respond alone. In the combination, the page receives A and S together, but D arrives only after A is released. The recorded maximum is 2/3, not proof that D is broken. Repeat D → S → A and compare the original application.
Conversely, a complete 3/3 attempt establishes only that these three selected positions reached this page together in that attempt. It says nothing about every other combination.
Give support a specific result
Record the selected keys, layout, order, isolated responses, maximum together and any interruptions. Export the local report and add the application and connection you compared. “A + S + D received 2/3 twice on this setup” is more actionable than “the keyboard has ghosting”.