Dim backlight and unresponsive touch screen after glass replacement?

A child cracked my screen 8 months ago and repaired it using a screen I bought on eBay because my warranty was void. I can't remember what I did but it worked great after I finished except the vibrate didn't work and no sound was coming out from the earpiece. I lived with that by using apple headphones.

I dropped my phone again and ordered another glass replacement from eBay and have just done that. After battling with ribbon cable #1 (it was somehow too long to click into place...) I have now set everything up. Turned it on, touch screen not responding. Reattached the ribbon cables, phone didn't turn on. Tried someone's advice of totally removing the logic board, phone now on but touchscreen still not responding and the screen is extremely dim.

Any advice/help/someone giving away free iphones??

Thank you!