Is my brother's phone unfixable?
The same thing happened to a friend of mine and according to him, the following solution worked:


Use the volume buttons to turn the phone off
Switch it on using the power button
If this screen appears again, reboot into fastboot
reset the phone via a windows computer



fastboot devices
fastboot erase userdata
fastboot erase cache
fastboot reboot




If nothing works, play around with the phone and learn something new!!