White Lines on iPod Touch 4th Gen LCD

I have replaced the LCD/Digitizer on this iPod, and when I plug the power in (or turn it on), if I leave the screen kind of there, but not pushed down all the way, it seems to work great. Picture is good, touch works, etc.

However, when I go to press the screen down (i'm test fitting before removing the cover from the adhesive), I start to get horizontal white lines. Once I see them, I stop immediately, because I don't want to damage anything.

What could be the problem? Could it be that I don't have the LCD cable plugged back in correctly/all the way? Is the LCD cable the one that plugs from the top of the logic board, or the one on the botttom?

Thanks