Chosen Solution
I replaced the screen and it worked fine everything was perfect but I took the old screen and removed the glass and tried to see if the lcd worked and plugged it into the phone but I didn’t so I just put the screen that worked right back in and put it back but now it wouldn’t turn on at all
Did you disconnect the battery before you unhooked the screen and reattached it? It sounds like you might have blown the black light circuit. Probably a filter. Put on the new screen and disconnect the battery before you unhook or reattach any connections. See if iTunes will recognize the phone. If it does hit the power button and in a dark room see if you can see an image on the screen. You can also use a flashlight on it. If you have an image and iTunes recognizes it you have blown out the back light filters and need to have someone who can microsolder to repair it. Update (06/08/2020) Most likely the battery should be fine. But it wouldn’t hurt to try another battery to test it.
