Having problems with new LCD screen

[Clarky5891]

Put a new LCD screen and front case on my iPhone 4 and all seemed well until a few hours later when I unlocked the screen to see the screen had turned negative. Took my phone apart again and checked everything but nothing changed. It has now started to flicker in a out and negative and normal as well as shadows and a near unreadable screen
Does anybody know what I may have done wrong or do I need to give it too a professional?

 

[Mysterion]

Make sure the connectors inside the iPhone 4 are connected all the way.