Yesterday I tryied to root my old leeco x620, but after type "fastboot boot twrp.img" command in adb, screen just turn off and now phone is actually dead. I was searching for similar problems and i found some tutorials but any of them cannot help. I was trying flash phone with SP flash tool but its not work im getting an error "[BROM] Can not pass bootrom start command! Possibly target power up to early." I couldnt find solution for this and now i dont know what more to do. Firstly, phone was connecting and disconneting to pc over and over but after using SP flash tool my pc detects device as "MediaTek PeLoader USB Vcom (Android) (COM5)". Any of combinations buttons didnt work. If someone have any idea plz help me 
