My galaxy S5 which i've had since early summer has been working fine up until this December, when it began to power off at random times, attempt to reboot, and then endlessly power up and restart on the "Samsung Galaxy S5 powered by Android" screen. Whenever i plug the phone into a charger when it is restarting it seems to be able to fully boot and allow me to use it again. What can I do to solve this problem?