Brightness function keys +/- cannot increase the brightness on display. Other function keys are working properly.
The above symptom may occur to the following systems:
IdeaPad Z500, Z400
The above symptom may occur under the following operating system:
Microsoft Windows 7, Windows 8.1
The issue is most likely related to a windows update that has upgraded the graphic video driver to version 10.18.10.3958 from 9/30/14 or 10.18.10.4276 from 8/17/15. These versions are known to cause loss of brightness control. Restoring the previous driver should also restore brightness control.
- Go to Device Manager
- Select Display adapters and scroll down
- Right click on Inter(R) HD Graphics4000 and select Properties option
- Go to tab Drivers in the pop up window
- Push the Rollback Driver button
- Wait until it is done. Your system should recover the brightness and the increase/decrease functions in the keyboard.
- If the previous step does not resolve the issue, please upgrade Intel Video Driver to the latest.
- Windows 7 Intel Video Driver: Download here
- Windows 8.1 Intel Video Driver: Download here
- Check to see if brightness controls have been restored using the brightness keys.