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I have a Lenovo y410p, and I am trying to install Ubuntu 13.10 in EFI mode side-by-side with a Windows 8 installation on a GPT partition. I have already disabled secure boot, and I have the LiveCD image running off a USB flash drive in EFI mode.

When I get to the GRUB environment, I have to modify the kernel arguments to put nomodeset=1 or the screen will be turned off when the kernel starts.

lsmod shows that the following modules are loaded for video:


The former is just the usual Intel graphics driver, and the latter is the open source NVIDIA driver.

When X starts, in /etc/X11/Xorg.0.log it reports that a screen was found but it was not properly configured, and then it shows "no screens found".

Starting with nomodeset=1 in Install Ubuntu instead of Try Ubuntu works fine.

After installation, the same issue occurs as on the live environment. No dice. Not sure where to go from here.

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The reason the screen was showing up black was because KMS (Kernel Modesetting) wasn't turning on the backlight for the Intel-backed screen. In Optimus, the Intel device gives the image to the screen device, and the NVIDIA device simply acts as a pixel buffer generator and is not actually attached to the screen.

Open /etc/rc.local and add the following line before exit 0

setpci -s 00:02.0 F4.B=30

The 30 may be changed to any value between 00 and FF. 00 is Full Bright, FF is Full Dark.


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