How to engage/turn on keyboard backlight for my Latitude 3520 (Intel Core i5)/(2G77ML3)?

Question

I've used the generic Fn + F5/F9 as those are the only blank Fn extensions on the keyboard but nothing happens. I've also just updated the BIOS system drive as it was in need of a critical update but now I'm lost. Am I missing something? I also can't remember where to go to engage the keyboard backlight manually.

Answer 1

Keyboard backlight is not a Microsoft or windows feature. It’s strictly a hardware/firmware feature. For the Dell Latitude 3520, the important detail is that the backlit keyboard is optional. Dell lists Fn + F5 as the keyboard-backlight shortcut, but only on device actually equipped with the backlit keyboard. It wouldn’t be a blank key if available but should show a some glowing keyboard icon. You might want to contact Dell support. Give them your device service tag, which can be found on the bottom of the computer. They can look up to tell you if this device should have backlit keyboard or not.

Answer 2

For a Windows-managed keyboard backlight on compatible devices, the manual setting is in Settings > Bluetooth & devices > Keyboard > Keyboard backlight. If the device supports automatic adjustment, the same area also includes Change keyboard brightness automatically when lighting changes.

If the keyboard backlight still does not respond after trying the function keys, the documented behavior is that keyboard backlight control depends on device support and host support. On supported systems, the host sends a Set Level report to control brightness. If that support is not present, the device may fall back to its own local brightness controls.

For Dell Latitude 3520 specifically, the exact hotkey combination is not provided in the available documentation here. The supported Windows location to check manually is:

1. Open Settings.
2. Go to Bluetooth & devices.
3. Select Keyboard.
4. Look for Keyboard backlight settings.
5. Adjust the brightness there if the option is present.

If that setting is not present, that indicates the keyboard backlight is not being exposed to Windows through the supported backlight control path described in the documentation.

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• Keyboard Backlight Implementation Guide
• Keyboard Backlight Implementation Guide
• Keyboard Backlight Implementation Guide