Chosen Solution
Battery was connected during replacement. One connector cable for the screen unplugged before I tried turning the phone back on. Display did not turn on. Phone got warm. Later I disconnected the cables. Later I disconnected the battery. I waited then reconnected the battery and then the screen cables and it got warm. I tired to turn the phone on/off. The screen did not turn on. The phone doesn’t respond to itunes or and the screen does not turn on for charging. So I can’t tell if the phone is on or off, but the connector cables still get warm even when not charging. This has happened before and I left it for weeks and came back later and I plugged it in and it magically worked. I don’t know what happened and I don’t want to assume that will happen again. Everything worked just before I replaced the screen. Update (01/20/2019) Never mind. I plugged the cable into the wrong one. It’s fine. Also, you guys scared the crap out of me. Thanks.
I plugged the cable into the wrong one.
The problem is most likely a blown backlight filter. Also if longer screws are put into the shorter screw holes for the screen (two lower ones) it can damage the circuitry on the phone’s logic board causing it not to turn on. Note that plugging a new screen while the battery is still plugged in can blow the filter (or worse other components on the backlight circuit). Make sure to always have the battery unplugged before unplugging and plugging screen cables in. To confirm it is backlight filter blown shine a flashlight on the screen and see if you can make out very dim image display. You can also try this while the phone is turning on, it would show apple logo but very dim. For backlight filter / circuit it can be fixed but only by someone that does micro-soldering on iPhones.
Having the battery connected while replacing the screen is your issue. Pretty much your phone is fried due to a short. Always want to disconnect the battery before anything else.
