iPod Touch 4th Generation has a black screen after opening it?

I deleted something off of Cydia and my iPod got stuck on the apple logo. My power button is broken so I couldn't just reset it. I got tired of trying to fix it so I decided to open it up and try fixing the power button but then I realized that I didn't want to break anything and stopped (I didn't open anything expect the screen). I connected the connector back but my iPod is still shut off/has a black screen. When I plugged it into my computer iTunes recognized it and I heard the sound of it being plugged in.