Xperia Z3 is just locked!

[Serkan751]

The Xperia Z3 I bought the day before was just locked this morning. It happened all of a sudden during standby mode. Battery level was 85%. Now, touch screen and start button do not respond. The phone cannot be charged. It does not connect to Sony PC Companion. The led light flashes "white". The first 40 hours I have been using it everything seemed fine.

What could be the reason and how can I fix it? How can I protect the personal / private info & files inside if I need to turn it in for repair or replacement?

[Thommo]

Have you tried the red reset button found under one of the side flaps or you could try holding power and volume up buttons for around 15 seconds which will have the same effect if these buttons are responding, If it does switch off then try to restart your device

[Serkan751 · Accepted solution]

Thanks, it worked. You are awesome! 

My "reset" button was yellow and under the cover for the SIM card holder, it read "OFF". I pushed it a little bit by the edge of a fork. The phone vibrated for a moment. Then I was able to turn it on. Now, everything seems fine. But, I still wonder what caused this so that I can prevent from experiencing the same problem again.

Should I still bring it to a Sony service to have it checked thoroughly?

[Thommo]

Think of a phone like a Pc which will also freeze and to fix it you have to hold the power button down or remove the power supply to switch it off then upon a reboot it's fine - A phone is exactly the same

[RickGM]

So are we saying here that the little yellow button simply cuts the power (an alternative to holding the off button and selecting Power Off)

[Serkan751]

In my case the off button did not respond so the little yellow button was the last and only option left. And it worked.

But I do not think its function is the same as the off button with regard to power management or resetting the phone. 

[Thommo]

Yes that button will cut the power from the battery or but is only to be used as last resort - The power and volume up combination promts the phone to prepare for a shut down