White screen...but different this time...

iPod 4th gen. Screen cracked. Replaced the screen per instructions. Initially the screen came up white. I cold booted it and got the Apple logo. I ended up having to pull the screen back up to peel off the protective covering on the back of the LCD--I believe the unit was on when I did this--the top video cable came undone, but I plugged it back in and sealed her up with the 3M tape.

It's been white screen ever since.

I've done everything:

--Home button + power button reset = White

--Home button + volume up + power reset = White

--Put it in recovery and reload the firmware = White

--I've pulled it apart and shorted out terminal 3 of the battery to reset = White

--I've put a total of 3 displays (owner bought the first, I bought 2 more because I felt bad) on this ipod thinking I had bad displays and other than that FIRST time of seeing the apple logo, they've all = White

--This last time, I went all out and pulled the rear-camera cable out of the back of the board so I could lift the board up high enough to make sure the video cable was seated correctly and...

White.

The computer recognizes it. It allows me to set it up through iTunes. It detects recovery mode and re-loads the firmware.

IT'S STILL WHITE!!

I was careful. I didn't torque anything. I didn't even rip the volume cable in the 50 times I opened this thing. What could I have damaged that caused the permanent white display?