have you installed any new apps? was there a update? if you hold volume up,home button,and power button
at the same time you will get to a screen that one of the options will be to clear cache partition use the volume down key till that is highlighted then hit the power key to confirm then use the down volume key to say yes and hit the power key again then just reboot. Hopefully this will help. Good Luck
Now phone is locked, won't let me do my security pattern. Won't turn on or off, just frozen. Keep taking out battery to try to restart. Still frozen.
Try taking the battery out and hold the power button for about 30 seconds then put it back in and try to reboot again if that does not work try here....Samsung Galaxy S 5 Support Troubleshooting | Verizon Wireless