Stuck on Black Screen, Reset gives code 4005

Here's the short of it:

1. Turn phone on normally with power button. Black screen (you can see the backlight come on) but no apple logo and computer won't even recognize it as a device that's been plugged in.

2. Restore mode (lock and home button while plugged in). Get the Apple logo but no iTunes logo or plug in prompt on iPhone but iTunes recognizes that it's a phone in restore mode needing reset. Download and apply reset, iTunes will attempt to reboot the phone and say "waiting for iPhone." Never gets past that, phone reboots gets to Apple logo and stalls. Then error 4005.

Screen was repaired with OEM parts (I had a dud iPhone 6 laying around and used the screen from it, so original OEM). I switched back to old screen too and same thing is happening.

This allll happened after update to iOS 10... sooo assuming something with that but can't get it to go back at this point. Right after the update happened the phone began acting "weird." Randomly turning off and on.

Good luck...