Black screen but lit after fixing

So I recently tried fixing an iPod 5th generation after we tried taking it apart and the screen cracked. We left it for a while (like 6 months - 1 year) and I decided to fix it. I put a new backing in red and everything was going fine. It was when it was charging the screen turned on and it had light, but no image. It is recognizable by computers but has a passcode. I gave it to a friend which also had a broke screen for an ipod 5th gen. The screen worked fine in his but not in mine so it's not the screen. I've tried disconnecting and reconnecting the ribbon cables and other things. Still nothing. I have no clue. I did research but nothing. I tried doing a soft reset (home button + power) and that's the only way there is light. I looked at this: ifixit.com/Answers/View/359374/Black+screen+but+backlights+on but it didn't really help. If it involves microsoldering then say it does and if there are any CHEAP mail in repair services.