Symptoms
- Keyboard backlight doesn't turn on at all
- Backlight worked before and stopped after an update
- Backlight key or shortcut doesn't seem to do anything
- Backlight works on some keys but not others
Likely causes
- CommonBacklight toggled off accidentally via a function key shortcutMost laptops with backlighting use a dedicated key or Fn combination that's easy to hit by accident.
- CommonBacklight brightness set to its lowest/off level in softwareSome laptops control backlight brightness through the OS or manufacturer software rather than a simple on/off.
- PossibleDriver or firmware issue after an updateKeyboard backlight control can be affected by keyboard or embedded controller driver updates.
- Less commonBacklight LEDs or their wiring have failedMore likely if backlight worked erratically before failing completely, or after a spill.
What to do
- Press the backlight toggle key (often paired with Fn) to confirm it's not simply switched off.
- Check manufacturer software (like keyboard or lighting control apps) for a backlight brightness setting that may have been turned down.
- Update keyboard and chipset/embedded controller drivers from the manufacturer's site.
- Restart the laptop to rule out a stuck driver process.
- If backlight worked in patches before fully failing, or a spill occurred recently, consider that hardware damage may be involved.
- Check if backlight settings reset after a BIOS/firmware update and need to be re-enabled.
Tools and parts
- None required
When to call a pro
If toggling settings and updating drivers doesn't restore the backlight and there's no spill history, a technician can check the backlight wiring and controller.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.