You can definitely back your data up. Even if the screen is broken or black.
First, boot your S5 into recovery mode like this:
- Switch your Samsung Galaxy S5 completely.
- Boot into Galaxy S5 recovery mode by pressing and holding Volume Up, Home and Power keys at the same time.
- Release all three buttons when Samsung Galaxy S5 screen flickers and the main screen of Recovery mode appears.
Your phone should now be in recovery mode. If your phones' screen doesn't show any signs of life during this process like some sort of flicker, repeat the process and check through adb with
until it shows your device id.
Once it shows your device id, enter the following in the command prompt
adb shell echo "persist.service.adb.enable=1" >>/system/build.prop echo "persist.service.debuggable=1" >>/system/build.prop echo "persist.sys.usb.config=mass_storage,adb" >>/system/build.prop reboot
Once you've completed that, you can download a free software that when run on your pc allows you to control your android device. Including touch response and swipe for screen unlock or password entry. The software is available at the link provided. I've personally tested this with multiple android phones including s3, s4, and s5 and it does work. (kids can be dangerous around phones :/).
Hope all this helps
Boot S5 into Recovery
Control device with broken screen