My screen doesn't display anything after replacement.

So, my touch screen wasn't working (Only the touch part) so I ordered one from amazon since my brother wanted to try replacing it.

The issue now is that when the phone boots up, the screen just produces a little feint light and nothing else. The touch screen works now, I can hear it.

The weird thing is that if we boot it up with the old screen instead, unplug it and switch to the new one after it has opened it works fine. If the phone is shut down again the problem recurs.

We are fairly certain that this isn't a hardware issue, but if it is please tell me.