boot loop - Samsung Galaxy S3 not booting up, keeps restarting showing ”Samsung Galaxy S3 GT-i9300” black screen

My Samsung S3 is stuck! It keeps restarting!

It doesn't reach the enter pincode, but keeps restarting showing the "Samsung Galaxy S3 i9300" screen. Then cycles starts again.

Here are the things I've tried:

• I have already removed battery, put back in; still the same result.


• I have also tried to hard-reset, but it just turns off and restarts.


• Same result when trying VOLUME DOWN + HOME + POWER BUTTON; goes back to restarting and the Samsung S3 screen.

It was working fine last night, but when I left to do something, I came back and found it restarting over and over again. Didn't update any apps.