The two touch keys, which are arranged on the right and left of the home button of your Samsung Galaxy S5 will be lit when operating. So you know even in low light conditions immediately where they are located. Now it may be that these touch keys are not illuminated on your Samsung Galaxy S5 and you ask yourself that question:
Is the lighting of the touch keys of my Samsung Galaxy S5 not working correct?
We can reassure you! In general, the lighting of the touch keys is not defective, but just disabled. This is due to the energy saving mode. If this mode is activated, the touch key lighting of your Samsung Galaxy S5 is automatically turned off to save battery power . So shall the touch keys lit again on the Samsung Galaxy S5 you have to either disable the power saving mode or adjust the settings.
We show you how you can adjust the power saving mode of the Samsung Galaxy S5 so that the touch keys continue to light if they are pressed. For this purpose, open the menu.
Go to Settings -> Section "Quick Settings" -> Power saving -> power saving mode --> restrict performance.
Here remove the check in the checkbox at "Turn off touch key light". The lighting of the two touch keys will now be active again on your Samsung Galaxy S.