iPhone Screen not turning on after taking screen off?

Few background notes:

- iPhone screen is cracked.

- Have replaced the screen myself but returned the new one due to a dead lcd whatever (month ago)

So a few nights ago my iphone suddenly went to a black screen. I could still hear notifications and such. My phone then powered on with the apple logo. The screen went black but was backlit and my assistive touch came up. I googled it and they said to squeeze my phone lightly by the lock button on the screen and the back. Did so and my phone powered back on.

Came home today with a new screen in my mailbox. I ran inside and took my screen off carefully. I then connected my new screen with out screwing it in. The logo came up then there was a red flash across the whole screen. Then the screen went black, then repeated the logo and the red flash. I immediately took the screen off and put my cracked one back on without screwing it in again. The screen lit up and function just fine. I then took it off and connected the new one. Nothing happened so I took it off and connected my old screen. The screen stayed black and never came back on.

iTunes recognizes my phone and so does my car (bluetooth). PLEASE HELP!!