HD 6870 Black Screen when starting Mac OS X 10.6.3 SL #iATKOS

Hello,



I hope you can help me here. I've installed Mac OS X 10.6.3 Snow Leopard with "Nawcom's Osx ModCD". I used this command: rd(0,0)/extra/modbin_kernel arch=i386 busratio=18 maxmem=4096. After that the install disk started. After install, I go back to windows (dualboot) and I replaced the legacy_kernel. But when I'm starting Mac OS X Snow Leopard, I got a weird screen (something like the ModCD). I wait... And after that my Radeon HD 6870 Fan become loud and the screen become black. So what is the problem? Did i do something wrong?







My Computer:



ASUS M5A78L-M LX



FX-4100 3,6 Ghz



Kingston 2x4GB 1333 Mhz RAM



AMD Radeon HD6870



2TB Hitachi Hard Drive (1TB(my stuff);750GB(Windows 8);250GB(Windows 7)



200GB Samsung Hard Drive (Mac OS X 10.6.3 Snow Leopard)







Thanks for helping me ;)







Sry for my english, I'm german :)