After screen replacement, my phone won't turn on. Why?

So first off….I'm not really sure if this is the correct phone. It might just be the LG Tribute Dynasty…when I remove the battery from the back it reads sp200…so I'm guessing tribute dynasty. Idk. Anyways

I ordered the part, replaced it. Put everything back in order…however, there's a black, sticky thing that's on the back of the LCD/digitizer that I moved from the old screen to the new screen…it's ripped and doesn't stick anymore. When I turned the phone on it turned on but all I see is black.

Before I fixed it there were dead pixels and could hardly see anything…now I can't see anything. It's frustrating.