Why won't my LG G3 d850 go past the AT&T logo?

A

AC Question

my lg g3 d850 wont go past at&t logo

so few weeks back i dropped my lg g3 and the screen cracked which led to the screen not responding. so ordered a new lcd and digitizer with the frame. today the new lcd came in mail today so i replace the cracked lcd with the new lcd but the bottom back panel with the speaker fell i stepped on it by accident and it broke so i put everything back together, accept the back panel with the speaker and turned the phone on and it wont go past the lg logo screen so i manually hard reseted it and after it rebooted it wont go past the at&t logo now. please give me solution asap