Apple logo then off after battery swap.

Hi all,

An iPhone 5s (Verizon, CDMA) has gone into a type of boot loop that I'm not too familiar with. About a month ago a customer came in to get a battery replacement and not the phone will not move past the apple symbol during the boot sequence. Everything was fine with the repair up until a night ago.

I've tried to change the battery, tried a different screen and tried a different charging port. Still all with the same issue.

I am noticing that when the phone is plugged in, I can see light coming out from between the metal back of the screen and LCD.

I'm totally at a loss here and hope you can help!