I’ve got an HUB75 display with FM6124S drivers. I debugged alot since it stayed black and after some time I tried other drivers.
Turns out it “works” with every driver but the intended one. If I choose a driver that is not FM6124 it lights up, shows the image but LEDs that should be off and are close to ones turned on flicker. A bit like blooming.
After finding that out I tried to fix the flickering but with no luck. Anyone got an idea why every driver but the actually correct one seem to work? The display is a few years old so it having the older FM6124 drivers checks out.