I’ve also opened a support ticket on this, but maybe someone here knows a solution.
I’ve finished my Picade build yesterday evening and I have a screen problem.
The screen does not light up at all (stays black), only the led on the controll panel lights up in red.
So far I’ve tried, without success:
reseating the flex cable several times (really seems to be seated correctely)
I’ve uncommented “hdmi_force_hotplug=1”
I`ve powered the screen seperately (not from the pi3)
I’ve connected a diffferent hdmi source (Nintendo classic mini :-) )
The screen stays black…
I finaly got mine to work after four months. I watched one of the builds on YouTube and noticed the person had done something not in the instructions. He attached a USB cord in between the screen and one if the USB ports. This gave the screen power. Earlier I made the tweek in the setup file mentioned in the white sheet but still nothing. That might of helped later but nothing worked until I added that USB cord.
Hope this helps.
I am still having other problems but am one step closer.