Why does the laptop's native display not work before loading OC?

Question

Lenovo

In general, I somehow demolished my native windows, installed ubuntu 12.04. And here's the trouble, the post-boot screen and the choice of OS, i.e. grub, stopped showing. I spent a long time steaming, and in the end I blindly chose another native display in bios, i.e. display / Analog (VGA). And a miracle! Everything was shown on TV. But what to do with the native display?
Laptop lenovo b590. Integrated video card. The native display itself works when it has already entered windows 8 or ubuntu, and in windows 7 there is a dark screen, but it enters the OS, I have not tried it on others (OS). UEFI is.