What other things I should try to fix my bottom screen for old 3ds xl?

My bottom screen does not put out display, just all black but the whole device turns on and everything works, just not the bottom screen.

I know the motherboard is the problem and not the ribbon cable of my bottom screen as I have tested the screen on a known working 3ds xl board and it is completely fine.

Now I'm stuck with what to look out for to repair. The 2 ZIF looks normal to me as far as my eyes can see, I do not have access to a microscope to look a little closer.

So before I do anything, what other things I should look out for other than the ribbon cables? Is it possible that a fuse is dead and which one are those? Thanks for the help