Black screen 2015 macbook air error code VFD005

I am having the VFD005 error code saying the problem with the display. I then replaced the display and assembly, no luck the error code still exists and the screen is still black. The webcam works and sound works, I can hook the macbook up to an external display and it works fine. I wouldn't think this would be a faulty graphics card since it hooks to an external and displays fine. What other possibilities are there with this problem? This is a 2015 early macbook air 13 inch A1466 (EMC 2925).