Thanks for confirming @Rocko
In 11.10 it definitely used to switch between the two monitors (laptop screen and external monitor). (I tried recently 11.10 on another L502X and the (Fn + F1) worked just fine.
In any case, in 12.04 ( Fn + F1 ) is the only BIOS key combination that does not work. Yet, it is a vital feature for multi monitoring and those doing presentations frequently.
I still do not know wether it's a kernel issue or just that the new Unity Hotkeys implementation conflicts with the Dell XPS 15 BIOS keyboard shortcuts.
Thanks for confirming @Rocko
In 11.10 it definitely used to switch between the two monitors (laptop screen and external monitor). (I tried recently 11.10 on another L502X and the (Fn + F1) worked just fine.
In any case, in 12.04 ( Fn + F1 ) is the only BIOS key combination that does not work. Yet, it is a vital feature for multi monitoring and those doing presentations frequently.
I still do not know wether it's a kernel issue or just that the new Unity Hotkeys implementation conflicts with the Dell XPS 15 BIOS keyboard shortcuts.