Keyboard backlights

Question

Keyboard backlights no longer work. When I power down then power backlists still don't work.

Answer 1

May I know your computer make and model? Have you tried using the keyboard shortcut (Fn + backlight key)?

Answer 2

Try these steps in order to isolate whether this is a hardware or Windows issue and to restore keyboard backlight functionality:

1. Check the hardware/backlight key
   On many newer Surface and Windows devices, the keyboard backlight is controlled by a function key. For newer Surface devices, the F5 key cycles through four levels of backlighting (off → low → medium → high). On some older models it may be F7. Press the backlight key repeatedly and also toggle the Fn key to ensure the function row is in the correct mode.
2. Confirm the keyboard itself works
   • Press Caps and Fn a few times and check whether their LED indicators turn on and off.
   • If the LEDs do not light at all, this suggests a hardware issue with the keyboard, and the device or keyboard may need service.
3. Test the keyboard in UEFI/firmware
   If using a Surface-type device:
   • Turn the device off and wait 10 seconds.
   • Press and hold Volume Up, then press and release Power while still holding Volume Up.
   • When the UEFI screen appears, test the keyboard (arrow keys, etc.).
   • If keys work in UEFI but the backlight still does not work in Windows, this points to a Windows/software issue rather than hardware.
4. Check Windows power and backlight-related settings
   On Windows 11, keyboard backlight behavior can be affected by power and lighting features:
   • Go to Settings > System > Power & battery > Energy saver and check if any option like Lower keyboard brightness when using energy saver is enabled. Try turning Energy Saver off or disabling that option to see if the backlight returns.
   • If the device supports automatic keyboard backlight brightness (with an ambient light sensor), go to Settings > Bluetooth & devices > Keyboard > Keyboard backlight and toggle Change keyboard brightness automatically when lighting changes off to test whether auto-brightness is keeping it off.
5. Keep keyboard backlight constant for testing
   For troubleshooting, ensure the keyboard backlight is not being automatically turned off or dimmed by battery or ambient-light features. Disable any automatic keyboard backlight adjustments so that manual backlight key presses have an immediate, visible effect.
6. Try another keyboard or device
   • Connect an external keyboard (if using a laptop) and see whether its backlight works.
   • If an external keyboard’s backlight works but the built-in one does not, the built-in keyboard hardware is likely at fault.
   • If neither works, the issue is likely with Windows or drivers.

If the keyboard LEDs never light (Caps/Fn or any backlight level) even in UEFI or on another device, the keyboard hardware likely needs repair or replacement.

---

References:

• Keyboard Backlight Implementation Guide
• Keyboard Backlight Host Behavior
• Device under test setup for battery-life measurements
• Troubleshoot Surface Pro Keyboard or Type Cover
• Troubleshoot Surface Pro Flex Keyboard
• Backlit keyboard - Microsoft Q&A