Z3c stuck in loop

[JohannesErdfeld]

Yesterday suddenly my z3c did a restart by itselt and now its stuck on loop. I only see the SONY logo for 2-3 seconds until it restarts again. 
Tried using pc companion to repair my software, it went sucesfully but it did not fix my problem. Still stuck on loop.

Could it be a hardware problem?
Pressing the yellow button to reset phone also doesent help.

[Christofer]

Hi @JohannesErdfeld, I'm very sorry to hear about this.

If a software repair using PC Companion or Xperia Companion didn't solve this behaviour I'm afraid your device is in need of repair. You can contact your Local support team for information on where you can find an authorised service center and how to proceed with this.

Let me know if you have any further questions about this.