DELL Inspiron 5770 - Sequoia - Graphics - so much tested - PLEASE HELP !

[Maccaroni]

I cant get  my graphics to work on internal Laptop-Screen, tested for days, i am not new, got 7 different Laptops making work fine with Sequoia, but this i don´t - I know its the right Device-ID, i extracted out of my bios teh correct Data and pacthed in Grubshell my DVMT - so it shoudl work, on an external monitor it works with acceleration on the interlan no picture, its not a backlight problem because its a black screen with backlight, so that is not eh problem, man this is really hard.

sshot123.zip