Flashing screen on 11.04

[~Aquatic]

I've just downloaded and installed Ubuntu 11.04 (amd64) and every time I boot i get a flashing screen. I didn't have any problems at all with the LiveCD. The graphics card and my wireless adapter worked out of the box. But after the install it won't work. I can choose the OS in GRUB and then there's a purple screen. After that the screen starts flashing and I can hear the login sound.

I have tried using "nomodeset" but that didn't work either. There is no flashing, just a purple screen all the time. But it was possible to enter tty. I also tried booting the Recovery Mode but it just loads and then a pink flashing screen appears.

The graphics card is a XFX Radeon HD6870 1GB.

Any help is appreciated.

[mirelon]

I have the same issue - running 10.10 until today with no problems. 9 hours ago upgrade to 11.04 popped, so I upgraded. After reboot there is only purple screen and then black screen is flashing with some white-on-black loading text ("setting up xy... [OK]" and so).

Please, someone help, because now I have unusable machine ...if noone can help, I would like to know how to downgrade to 10.10 - still better than flashing screen.

[mwedemeier]

I am also having a similar problem. After upgrading my screen is mostly black after the grub screen. I get a slight flicker of color, mostly like static. I have an Nvidia card.

[Hedgehog1]

Please do this (for all three posters above) :

gksudo gedit /etc/default/grub

and change this line:

#GRUB_GFXMODE=640x480

to this:

GRUB_GFXMODE=640x480

Then save and exit the document.


Then do:

sudo update-grub

The Hedge



p.s. ~Aquatic - you MAY need one more setting - but this should get you most of the way there.

[mwedemeier]

Sorry for the noob question. How do I get to a terminal screen? Once I leave the grub screen, I can't see anything. This includes Recovery mode. Right after I choose the OS on the grub screen my screen goes black with static color.

[mwedemeier]

I was able to boot up under the previous linux versions (2.6.35-27-generic) option. I did what you said and rebooted again. I still get the same issue.

[sikander3786]

Can you hear the login sound? If so, please press Ctrl + Alt + F1 at the blank or hang screen and see if the tty1 appears. If yes, login using your credentials, if it doesn't appear, from the Grub menu (you'll need to press and hold <Shift> key from Bios screen) select 'Recovery Mode' and then 'Drop to root shell'. Follow the commands below.

sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.old

Note, capital 'X' for X11. The commands are case-sensitive. If it returns an error like file not found, no problem, proceed to the next command anyways.

sudo dpkg-reconfigure xserver-xorg

sudo reboot now

Lets hope you can see the desktop now. If you can't, we will need to see the outputs of these commands.

lspci | grep VGA

glxinfo | grep Vendor

[mwedemeier]

I am getting the start up sound. In fact, it even sounds like I can log in.

Ctrl+alt+F1 did nothing.

I can see the recovery option in Grub, but when I select it, it gets to "loading RAMDISK." Then I get the black screen again.

[sikander3786]

I am getting the start up sound. In fact, it even sounds like I can log in.

Ctrl+alt+F1 did nothing.

I can see the recovery option in Grub, but when I select it, it gets to "loading RAMDISK." Then I get the black screen again.

If there are multiple kernels, did you try the Recovery Mode from an older kernel?

[mwedemeier]

For some reason I am able to boot into the desktop if in the grub I press 'e' , then add the line 'nomodeset.' However, each time I reboot I have to redo this. Also the resolution is 640*480, I think.

I tried your steps 1-3 once I got in and that did not work.

lpsci | grep VGA

I get:
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: nVidia Corporation GF106 [GeForce GTX 460M] (rev a1)


glxinfo | grep Vendor

I get:
The program 'glxinfo' is currently not installed. You can install it by typing:
sudo apt-get install mesa-utils