Hey MaLd0n,
I would like to thank you for your support, first.
I tried different framebuffer patches from that guide.
When I wake my computer up with opening the lid, all graphics works fine, no problem.
That's what I cannot understand. Only booting goes to black screen (as I think into Clamshell Sleep)
Even there were days, when it was booting fine. Suddenly, next day started booting into black screen again with nothing changed.
Thanks