changed screens

[trayluv73]

I hard bricked my note a month ago so I decided to buy one off of Craigslist that was working and all I had to do was replace the screen. I had an AT&T phone so I made sure I purchased the same model. I took the broken screen out of the phone and replaced it with mines. No broken cables everthing secure but when I turn on the phone the screen is crazydark! I turned the brightness to the max and can barely see the screen. I have to goto the bathroom with the lights off just to see 70% of the screen!I checked the cables and I dont see anything wrong. Help please what went awry?!