HElp,please Lg 90D410 boatloader bricked

HI, MY problem is that my lg90D410 stopped on the logo...and later the boatloader is not recongized and usb too.. I rooted it before .
I tried to solve the problem with that way linked below> on youtube search i can not put link..sorry
lG L70 Tips and Tricks - Part 6: Restoring Download Mode and Restoring to Stock
IS it the SOLVE of my problem ?:rolleyes:
But i did not find LG LAF Recovery Multitool in any where i googling it but not found also ..

Please Help me:( :(