Here's the Flashing Procedures of ASUS Zenfone 2 2GB [ZE550ML].You need this tutorial if you have experienced software problems in your Asus Zenfone 2 like Hang In Logo,Freezes and Force Close..
Now, Just follow the tutorial step by step, hope you success.
1. Power off your device first.
2. Push on "Volume up button" + "Power Button". Hold until "Fastboot Mode" appear.