Phone locks itself, asks for PIN instead of pattern lock

[AC Question]

I have a Samsung galaxy s4 & I always use a lock pattern, not a pin. This happens once in a while and it completely locks my phone, no phone calls, messages or alarms go through (I've been late for work because the alarm didn't go off) and my phone was simply on a surface, nothing was pressing against it so it's not like there were too many wrong tries to unlock it. It happened today while it was charging, when I pressed the home button after it being so silent for a very long time, I realized why. The screen simply says "Enter new pin ___". It's very frustrating.

 

[H3aTeRzz]

Hi

Try clearing the cache partition in recovery mode. See if that helps. Clearing the cache partition will not delete any data nor will it change any of your settings.