Replaced display assembly, now the screen intermittently turns black

Phone touchscreen cracked. Ordered a replacement off of this website. Followed directions. Replaced it. Worked great. A few days later, the display would turn black. At first, I would have to spam the lock button until it would revert back to the lockscreen. Now, that is useless. I have to cover the light sensor with my finger and press hard while pressing the lock button, and then the phone display turns on. It works every time and now I'm a little less anxious because getting back into my phone every 15 seconds doesn't take 10 minutes.

Now, the display IS getting power. There is a difference between this "blank" screen and the phone's "black" screen when it is powered off or locked. I can see light coming from the phone's bezel, especially the top. It works absolutely fine the 30% it's functional now.

So far, I have restored the iPhone through Itunes. I have reassembled it three times. The third time I cleaned the three display assembly wire contacts with 91% Isopropyl alcohol and a qtip. The phone continues to malfunction.

It's gotten to a point where after getting the lockscreen to show, I have about 10 to 15 seconds before it blanks out.

Also, every now and then - the screen will begin at the dark "blank" screen and then quickly and steadily fade to a bright white. I have absolutely no idea what is going on. I have spent the past 4 days reading and watching videos on this but everyone keeps saying to do a force restart haha. Please help!