I have an old netbook Acer AO751h with Lubuntu 14.04 and due to screen problems I can boot it only with kernel parameter acpi=off but this has the following issues:

• When I shut it down and shut down procedure is done I have to press the power off button,


• I cannot get the battery status as well.

So I tried to use the following kernel commands:

quiet console=tty1 acpi_backlight=vendor acpi_osi=Linux acer_wmi.blacklist=yes mem=992mb

But on boot I get a blank screen. The original problem is that without acpi=off I get a "tearing effect" or the screen shows random letters without even booting into Xorg.

Do you fellas have any idea how to fix that?

Edit 1

I tried:

quiet acpi_backlight=vendor acpi_osi=Linux acer_wmi.blacklist=yes mem=992mb

And I get a screen with a cursor blinking after a while random letters are being thrown.

I also tried with mem=1920mb and some random lines I get over my screen.

Edit 2

By also removing the mem=992mb I get the 'tearing effect' on Xorg the parameters I tried are:

quiet acpi_backlight=vendor acpi_osi=Linux acer_wmi.blacklist=yes

Edit 3

I also tried the same with Lubuntu 16.04.2 and still got same problems only acpi=off seems to work. Is there a way to disable only the backlight?

On both Lubuntu 16.04.2 and Lubuntu 14.04 you should boot with the nolapic boot parameter. In my case with the same netbook it booted like a charm. Also provides full shutdown/reboot functionality as well.

So the correct parameter boot order is:

quiet splash nolapic

You can do it by editing the GRUB_CMD_LINUX_DEFAULT entry into /etc/default/grub by:

sudo nano /etc/default/grub

(Use Ctrl+X to save)

Then run:

sudo update-grub