Re: my samsung galaxy s5 is frozen will not switch off
You can do one of two things:
1) Hold the power buttons for 5-10 seconds and the phone should shut off
2) Take the back cover off and pull the battery. Wait about 5-10 seconds then reinsert the battery and start the phone.
It could just be an app that crashed and froze the phone. It happens. Not often, but it happens.