Depending on the manufacturer, put a Android smartphone in safe mode may vary slightly and Samsung is one case where this is done differently.
We turn off the phone.
We light the Galaxy S6 while holding down the power button until the Samsung logo is displayed.
Now, once that is done, we release the power button and press the volume down button until the terminal is turned completely.
If you did well you will enter the insurance directly mode and take slightly longer than normal because you have to apply the theme but, once inside, appreciate the symbol bottom left putting safe mode and you will see that most applications that are not already have installed on your phone.
Besides the permanent notification is a button in the notification bar that indicates that we are in safe mode and will be our path to normal mode, for which the phone will restart again and enter the usual manner with all applications were running as usual.
In safe mode you can see some applications that cause problems such as continuous restarts, extremely low autonomy and some other things. This way you can see if the problem is software or terminal. We also allow you to uninstall any application from the insurance, so useful if you have installed an application and the terminal will not start now.
When finished just click on the notification and the phone will reboot returning to normal, it is a temporary tool that many do not know their existence but works pretty well. Some users even know of its existence. Did you had tried before?