An MX Keys key that no longer works even though it presses normally (the mechanical click is there, but no character appears) is more complex to diagnose than a mechanically broken key. It is not a key or hinge issue — it is an electrical contact problem between the scissor and the underlying membrane, or a firmware/driver problem. Before ordering anything, test on another OS to isolate the cause.
Diagnostic
Run this test in order: (1) test the key on another OS (Windows/Mac/Linux) — if it works elsewhere, it is a Logitech driver to reinstall; (2) test with the USB receiver and with Bluetooth — if only one method works, it is a radio issue; (3) test via USB-C cable directly — if that works, it is the wireless module; (4) if the key stays silent on all OS and all modes, it is a membrane defect under the scissor — disassembly required to repair.
Méthode
- 1
Test the key on another OS to isolate hardware vs software.
- 2
Reset Logi Options+ and unpair/re-pair the Logi Bolt receiver or Bluetooth.
- 3
Test wired via USB-C — if it works, it is the radio module.
- 4
If nothing works, contact us via the Contact page for a workshop diagnosis.
FAQ
All my keys stopped working at once — is it serious?
Probably a discharged battery, lost pairing, or driver issue. Plug the keyboard via USB-C to test with native firmware. If it stays silent, the motherboard is the issue.
One key types a different character — ghosting?
Check your layout in OS settings: if the system layout does not match the physical layout, some keys will type the wrong character. Cosmetic, not hardware.
My key works on Bluetooth but not with the Logi Bolt receiver — why?
May indicate a desynchronized firmware. Launch Logi Options+, disconnect/reconnect the keyboard to the receiver, and update the firmware. If the issue persists, the receiver may need replacement.
A key that types nothing is rarely a keycap issue. Follow the diagnostic in order before buying any part.