Backlight of screen is working, but why is there no display?

My iPhone screen got cracked.. I bought a new digitizer and used a YouTube video to disassemble and reassemble the phone. All went pretty smoothly. But when I turn on my iPhone, only the backlight works. I know the phone is working because my computer recognizes it and switching from mute to non-mute, the phone vibrates.

I've hard resetted it, and restored it via iTunes without luck. I'm also sure it's connected properly, have checked a few times.

Also when I hook up my old cracked digitizer, that one does work! Is the new digitizer I bought broken ?!