Boot Loop that occasionally turns into a blue screen

Working on a 5s. This repair started as a standard replacement of a cracked screen. This phone was working fine prior to repair with home button, volume, mute, both cameras ect. working as they should.

Opened phone up, unplugged home button cable, disconnected battery, took off emi shield over cable connections, transferred parts from cracked screen assembly to the new one.

Plugged LCD, Digi and front camera cables into logic board...all of them snapped into their connector with no problem. I did not reinstall emi shield over cable connectors yet since I wanted to test everything before zipping it up all the way.

So, Plugged battery back in, plugged home button cable in, then turned phone on to test before completely closing phone up.

Now this phone is boot looping. The white apple will appear for about 60 seconds then the screen switches to a solid blue screen for about 2 seconds, then switches back to the white apple....over and over and over.

I tried replacing the rear camera, but no luck. I tried unplugging the front camera cable, but again no luck. I was thinking that maybe the screen had been replaced before and the tech who did that repair screwed the long emi shield screw into one of the short screw holes thereby causing logic board damage. But if this were the case, how was the phone functioning before I started my repair?

I've tried a soft reset with no luck, I tried hooking the phone up to iTunes thinking that maybe the IOS needed to be updated, but iTunes doesn't even recognize that the phone is plugged into the laptop. Any ideas on what to do from here?