press vol down and power key on phone it ill show fastboot comant mode connect it to usb cable make sure drivers are Installed
now type the command
fastboot flash recovery recovery.img
after flash type fastboot reboot
now your phone will goto download mode unplug the cable and battery now put bater back in and phone will start up normally if your rom is fine else install rom search on google
it works for me best of luck for you .......