The top LCD screen on my 3DS XL (Pre 2015) is black, Lower works fine.

Hello. I recently replaced my lower touch screen upon finding it to be the cause for my DS to not turn on correctly. I used to be able to run my 3DS, i would just only be able to see my top screen, and it would shut off after a minute. I replaced the bottom screen and It works fine. My 3DS works completely fine, performance wise. Only one issue. When i turn it on, my top screen shows black, but glows as if its turned on. My 3Ds works perfectly. No crashes, turn offs, and i can use it just using the bottom screen. The only issue is the top screen now not works for some reason. It did work when my bottom screen was broken, however since ive fixed it its been only showing black. Ive taken it apart, and put it back together again multiple times, making sure each ribbon cable looks fine and dandy, and that its plugged good enough in all the right places. But nothing has worked. Anyone have anything? Anything, suggestions, questions, and answers alike are helpful!