3DS boots but no picture on either screen

I recently purchased a 3DS XL with a busted frame for cheap. All three ribbon cables coming from the top screen were severed so I fixed all of that - all new components. Now when I boot it up, it turns on just fine and I can hear the cursor move, background music, etc. The backlight is also coming on. The problem is both screens are completely black. I’ve tried reseating the ribbon cables, unplugging and replugging in the WiFi board and totally disconnecting the camera cable. There is also no SD card in this unit. I tried with and without one, including an SD loaded with CFW in case maybe the 3ds was modded and missing a file. Any ideas? Google only shows me results for the New 3ds, which this is not. 😢