hmm. with the new dsdt, did you upgrade/re-install the ACPIBacklight kext?
is it off/black or backlight dark ... can you try to increase the brightness with the Pause key?/
it is black,just like the graphics card has no Driver..
may be i have something wrong when upgrade the new kexts..
after reinstall the ACPIBacklight.kext and rebuild kext cache, no problem with the new dsdt..
great thanks .