Nee help to repaired Nokia x Dead boot

i received Nokia X totally dead ,according to customer a shopkeeper flashed his phone and he turned his phone dead .
I got ATF Box but I don’t know how to repaired dead boot
Is there any way to repaired dead boot without motherboard soldering pinout
I want to repaired throw USB cable .
I would like to repaired dead phone willingly as I love flashing It Would be a good experience of my life