So normally, my Fn key works fine. Every now and then, however, usually after restarting or hibernating, it will stop working. Bizarrely, I will still be able to adjust the brightness using the Fn key, but the pop-up indicating the brightness will not show up like it's supposed to. If I restart once or twice, it will start working again like it should. It has always done this as long as I can remember.
Please do try these troubleshooting steps that may help in solving the issue.
- Start by uninstalling/reinstalling the keyboard driver.
- Go to Device Manager and uninstall the keyboard driver.
- Reboot your laptop and it should reinstall the driver automatically.
- After the reboot do also change some settings in Power Option that maybe causing that problem as well.
Open Power Options and click on Change plan settings then Change advanced power settings on the next screen.
- Expand Hard disk first then set Turn off hard disk after to Never.
- Expand Sleep and set Allow hyrbid sleep to OFF and set Hibernate after to NEVER.
- Click Apply and OK.
- Do open Device Manager next and set your keyboard and Mouse to wake up your PC.
- In Device Manager right click on Mouse/Keyboard and select Power Management.
- Make sure there's a check on Allow this device to wake the computer and click OK.
- Do test your PC again after doing all these changes.