Screen shows black and brightness slider doesn't work

[mpyuri]

Hey, I have a i9500 phone and I flashed Perseus kernel on my roms (and also got a rom for 4.4.2 - NeatROM) and the result is that the brightness is stuck on the highest settings and the slider does nothing. Also, when I try to lock the screen and turn it on again - The sub keys work and it unlocks just fine but there's no picture and it's completely black unless I restart it and don't lock the phone again. Have any suggestions?

[AndreiLux]

You probably have some newer display panel that isn't compatible. Unfortunately I have no idea what causes it and AOSP ROMs have some differences in their kernels regarding the power-on sequence of the display.

Since this only affected maybe a hand full of people till now, I can't pinpoint the issue and can't help out.