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My laptop screen reduces light on dark applicatins
February 26, 2017
Edited: February 26, 2017
November 24, 2022
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Temporary change for current session
To enable or disable the Ambient Light Sensor (ALS) using the keyboard:
- Hold the Fn key and press the 🡸 key to enable or disable ALS.
- Hold the Fn key and press either the 🡹 key or the 🡻 key to disable ALS and set the LCD brightness manually. Pressing the 🡹 key brightens the display, and pressing the 🡻 key dims the display.
From (What is the Ambient Light Sensor feature on a portable computer - Dell)
Permanent change across boots
You can turn off Ambient Light Sensor (ALS) within the BIOS. However, older posts in some forums suggest the BIOS (Press F2 on boot) didn’t provide options for disabling the ALS. Answers on those forums say a BIOS update from Dell was necessary.
If you don’t find an option in BIOS for turning off ALS permanently, check Dell support site for BIOS update. Entering your system tag number is the easiest method else you’ll have to manually locate the relevant drivers.