- Install tool AsusFlashToolInstaller
put the phone on Droidboot by mode: shutdown then holding Power + VL UP.
connect your phone to your computer using the micro USB cable and launch the Asus tool Flash Tool.
Select the appropriate machine model
example: choose A500CG Zenfone 5
Browse to the folder containing Rom:
ex : WW_A500CG_126.96.36.199_20140731_6736-user-fastboot-user.raw
Under Wipe data if you want to delete all the data, select Yes, and vice versa, but the advice is that you should delete all data when Flash.
Select the USB cable as shown on.
Flash image successfully . goodluck