I replaced my screen but now have blue lines across it

Hi all

I replaced my screen on my iPhone 4 but now when it powers on all I can see is a screen full of blue lines horizontally and vertically. It was originally water damaged so I took it apart to dry it out and clean it up, then when putting it back together for the first time I trapped the LCD ribbon, and being impatient I tried to pull it through and it snapped. When I switched it on after the first rebuilding the screen came on ok asking me to unlock it but I couldn't use the touch screen function. I figured this was because of the snapped ribbon. Therefore I ordered a new screen with new LCD and digitiser connections. I was very careful in putting it all back together following the instructions on ifixit and making sure the ribbon was pulled through, however when I go to switch it on now I am now only getting light and dark blue lines (and possibly some faint red lines). It doesn't show the apple logo, battery logo, or any image other than the lines. Please help! I need to know if it's worth taking it all apart for a 3rd time or if there is a fault somewhere else (or a quick fix!). Thanks!