So I got a good deal on this GBA SP with a broken LCD and found a replacement LCD on Ebay.

I'm replacing the broken LCD with a different type than the one I took out. The basic structures of these displays are completely different. It's the lighting that's giving me trouble. The lighting on the replacement unit works completely differently than the original. It's an LED in one corner of the LCD frame. When it's active the colors on the screen are completely washed out. Is there something elseo I need to do to get this display to work properly? I know I'm probably not explaining this well but I just wanted to see if anyone else has some insights here. Thanks.