Black Screen of Death - Replaced Motherboard

A little back story about myself. I am a pc repair technician and have over 10 years of experience fixing various electronics. I also have my own repair business. A client has brought me a Nintendo 3DS XL 2015+ model. The unit has the "black screen of death".

When turned on I can hear the menu music but there is no display. If booted into safe boot mode, both of the screen are operational. After doing some research it appeared that motherboard may need to be replaced to resolve the issue. I have replaced the motherboard with no change.

Is there something else that would be causing this issue? Any other items I should check? Could it be that I just got a defective replacement board?

EDIT:

After more troubleshooting I have discovered there is a problem with the camera(s). The unit powers on and is fully function when the camera ribbon is unplugged