Symptoms

You cannot change the screen brightness outside of the Operating System when switchable graphics have been turned off The internal LCD brightness on these computers cannot be adjusted outside of the operating system (OS) when switchable graphics are disabled. This is using either the brightness sliders for battery or AC-power, or the keyboard shortcut in the BIOS methods. However, both methods work as intended when the switchable graphics are enabled or you are in the OS. Note: The brightness can still be modified using the keyboard shortcuts in Windows 10 with switchable graphics enabled or disabled. Systems specific to the issue: Dell Precision 7530 Mobile WorkstationDell Precision 7730 Mobile WorkstationDell Precision 7540 Mobile WorkstationDell Precision 7740 Mobile WorkstationDell Precision 7550 Mobile WorkstationDell Precision 7750 Mobile Workstation

Cause

Not Applicable.

Resolution

Note: This is a limitation of the technology involved. It is not a fault with your computer. Your computer is working as designed. Dell has moved to using UEFI mode only in the BIOS. However, the current switchable graphics technology from Nvidia does not support using the brightness controls outside of the operating system. The graphics output protocol does not support this. Note: If you are seeing a different issue with your LCD's brightness, please check out the following article: How to Troubleshoot Display or Video Issues on Dell Laptop LCD Panel

Support Cases