Hardware Left on Dpad not working after screen repair.

[tronsonic]

I just repaired the screen on my New 3DS (not xl) and once I put it back together the left button on the d-pad is no longer working at all. It still feels snappy like normal, I checked the contacts and it looks fine. I reseated all the ribbon cables probably 10 times now, but it's still not working. all the other dpad buttons are functional. I'm at my wit's end I have no idea what to do. The dpad was working perfectly before I took it apart.