my computer Configuration：
if i restart from mavericks 10.9 ,i can't see bios，it's black screen .Then into win7 system ,also black screen.but i can listen boot music。
Who can help me? Tanks a lot.
boot with chameleon。I also try clover ，but black screen.
if i Press the power button to shut down ,then press again i can see bios .and it works fine。it has QE/CI
Tonight I found something ,if i delete HD4000.kext ,it's normall，if mavericks load ,then boot it's black screnn。