On a full-size MX Keys, the numeric keypad is switched on with the Num Lock key, top left of the keypad. If the keypad moves the cursor instead of typing digits, press Num Lock once. There is no Num Lock light: Logi Options+ can show the state on screen. The MX Keys Mini has no keypad.
Where is Num Lock on the MX Keys?
On full-size MX Keys keyboards, the MX Keys S included, Num Lock is the first key of the keypad's top row, to the left of /, * and −. It has no indicator light: the MX Keys does not show on itself whether Num Lock is on, which explains most "broken keypad" reports. The MX Keys Mini has neither a numeric keypad nor a Num Lock key.
Why the keypad types arrows instead of numbers
With Num Lock off, the keypad keys switch to their second function: 8, 4, 6 and 2 become arrows, 7 and 1 Home and End, 9 and 3 Page Up and Page Down, 0 Insert and the decimal point Delete. Pressing Num Lock brings the digits back. The state is kept by the computer, not the keyboard: on Windows it can fall back to "off" at every start-up.
Show Num Lock status on screen
Since the keyboard has no light, Logi Options+, Logitech's software, can show an on-screen notification when Num Lock or Caps Lock changes state. Open your MX Keys in the software and check that these notifications are enabled; exactly where the setting sits depends on your version of Logi Options+.
On a Mac
macOS does not use a Num Lock mode: on a Mac, the MX Keys keypad types digits without having to switch anything on. If the keypad does not respond at all under macOS, look elsewhere: the keyboard connection, the input source chosen in System Settings, or a damaged key.
Num Lock key broken or missing?
If the key itself has come off, cracked or no longer presses down, it can be replaced on its own, hinge included, for €9.99. It clips on in seconds, with no tools and no settings to change.
Diagnosis
Three cases. (1) The keypad moves the cursor instead of typing digits: Num Lock is off, one press fixes it. (2) Num Lock turns itself off every time Windows starts: the computer resets the state, not the keyboard. (3) Neither Num Lock nor the keypad responds: test the keyboard on another computer; if only the keypad stays silent, the key or the contact under it is at fault.
How to fix it
- 1
Press Num Lock once, top left of the numeric keypad, then type a digit to check.
- 2
In Logi Options+, open the keyboard and turn on the lock-key notifications: Num Lock status will show on screen at every press.
- 3
If Num Lock turns off at every Windows start-up, enable the NumLock-at-boot option in the BIOS or UEFI, or turn off Windows Fast Startup, which often restores the previous state.
- 4
If the Num Lock key no longer responds while the rest of the keypad works, lift it off: a broken hinge can be replaced, and so can the key if it is damaged.
FAQ
Does the MX Keys have a Num Lock light?
No. The MX Keys has no Num Lock indicator. To check the state, turn on the Logi Options+ on-screen notification or simply type a digit on the keypad.
Does the MX Keys Mini have a Num Lock key?
No: the MX Keys Mini has no numeric keypad, so no Num Lock key.
Can I set Num Lock on by default?
Yes, on the computer side: on Windows, enable NumLock at boot in the BIOS or UEFI where the option exists, or turn off Fast Startup. The keyboard itself does not remember the state.
How much is a replacement Num Lock key?
€9.99, hinge included, in QWERTY and AZERTY. It clips on without tools.
An MX Keys keypad that types arrows is rarely broken: Num Lock is off, and one press brings the digits back. With no light on the keyboard, Logi Options+ can show the state on screen. If the Num Lock key itself has broken, it can be replaced on its own.
Parts for this repair
Genuine used keys, taken from dismantled keyboards and supplied with their hinge. The rubber dome is sold separately.