Detach the keyboard from your Surface Pro.
Inspect the magnetic connector and the contacts on both the keyboard and Surface for dust or damage.
Wipe the contacts gently with a clean, dry, lint-free cloth. Do not use liquid.
Reattach the keyboard firmly and restart the Surface using the touchscreen.
Detach the keyboard.
Select Start → Power → Shut down and wait until the Surface is completely off.
Press and hold the Power button for 20 seconds.
Reattach the keyboard and test it.
If it still fails, test the keyboard in Surface UEFI:
Shut down the Surface and wait 10 seconds.
Press and hold Volume Up, then press and release Power.
Keep holding Volume Up until the UEFI screen appears.
Try the keyboard's arrow keys to navigate.
If the keyboard works in UEFI, the problem is likely in Windows or its drivers.
- If it does not work in UEFI either, a keyboard or connection hardware fault becomes more likely.
See: