8+ stuck on logo/loading

My partner attempted his first 8 plus lcd replacement. He is now no longer allowed to attempt phones lol. The phone stayed on the logo screen and would go blank once in a while when powered back on. Tried disconnecting and reconnecting it all. There seemed to be issues with his transfer of the earpiece/front camera so we tried a different lcd with earpiece and camera built in and transferred the home button from the original screen. Same result so tried the volume up, down, side button and connected to iTunes for an update. Now phone is stuck in a loop of loading on the logo screen even when disconnected from iTunes and the PC. Is there a solution or some suggested fixes to try???