Find the Key That Doubles
Open the keyboard test and type a few sentences at your normal speed. Then press each suspect key on its own 20 or 30 times.
The test flags chatter when a key registers again within 30 ms of being released. Nobody can press a key twice that fast, so a flag there means the switch bounced.
The test ignores auto-repeat. Browsers mark a key that is held down and repeating automatically, so a held key doesn't count as chatter.
Clean Under the Key
Logitech says dust and debris beneath the keycaps and near the switches are a main cause of keys that register repeated keystrokes.
- Unplug the keyboard, or turn it off if it is wireless.
- Use compressed air or a soft brush to clear dust around the key.
- Plug it back in and run the keyboard test on that key again.
Logitech suggests cleaning a switch-based keyboard once a month so dust doesn't build up.
Check the Connection and Power
- Connect the keyboard or its receiver straight to the computer, not through a hub, extender, or switch.
- On a wireless keyboard, replace the batteries or charge it fully.
- Keychron says a cable other than the original can supply too little current and cause repeating keys. Use the cable that came with the keyboard.
- Update the keyboard's firmware with the maker's software, if it has any. Keychron also suggests a factory reset.
Then try the keyboard on another computer. If it doubles there too, the fault is in the keyboard, not the computer.
Check the Keyboard Settings
Logitech says delay and repeat settings, or accessibility features, can affect how keys behave. If letters repeat only when you hold a key a little long, the repeat delay may be too short.
- Windows: open Settings, then Accessibility, then Keyboard, and turn on Filter keys. Microsoft says it sets the keyboard to ignore brief or repeated keystrokes. Holding the right Shift key for eight seconds also turns it on and off.
- Mac: open System Settings, then Keyboard, and drag the "Delay until repeat" slider to a longer delay.
- Mac: under System Settings, then Accessibility, then Keyboard, Slow Keys sets an acceptance delay before your Mac responds to a key.
These settings hide mild chatter. They don't repair a worn switch, and a long delay can make fast typing feel slow.
Replace the Switch or the Keyboard
If one key still chatters after cleaning, its switch is likely worn. Keychron says a key that keeps repeating may be a switch problem. On its hot-swappable boards, you can change the faulty switch for a working one.
- Hot-swap mechanical keyboard: pull the switch and fit a new one of the same type.
- Soldered keyboard or laptop: contact the maker. Opening the keyboard or desoldering a switch yourself may void the warranty.
- Logitech keyboards: if the steps above don't fix it, Logitech suggests contacting its support about a repair or replacement.
After any fix, run the keyboard test again and type a few sentences to confirm the letters no longer double.