Long story short, I fried up my nVIDIA video card on the Lenovo ThinkPad T520 and did a stupid setting in BIOS to force to use that video card. Without surprise the screen is black when I boot the laptop though it still have a fully functional HD4000. So the question is: is there any way to reset the BIOS physically without changing the chip so that the config for display will go back to use optimus by default? Or any other idea helping me out is welcomed.
To reset your BIOS: