I'm running 11.04 on a 2011 13" mackbook pro (intel hd 3000 gpu).
Previously everything had been fine, but today when I plug in an external monitor (17" Acer being plugged in via a mini display port to VGA adapter) the laptop immediately recognizes the monitor, but the screen turns black. It seems that everything is still responsive. I can see the cursor and I can see it change as it moves over things like text boxes or the edges of open windows. But even after unplugging the monitor, I can't get anything but a black screen until I restart gdm.
Yesterday I was using the laptop with a 22" Asus monitor using a mini display port to DVI adapter and everything was fine. This same monitor was also working fine last week when I was running OS X, and on an older HP laptop without an adapter (straight to VGA).
How can I fix this?
Just found the official bug page, with possible workarounds such as installing other kernel versions: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/745112
For the time being, it seems we have to wait or play with other kernels...
EDIT: I've just installed and tried kernel
linux-headers-2.6.39-020639rc4
and works like a charm - at least in this regard. I hope it's as stable as the previous one as well!Installing a new 2.6.39 kernel solved a problem in my case. Here are step by step instructions for less experienced users: http://blog.lome.pl/blog/ubuntu-11-4-black-screen-problem-solved/
I am running Ubuntu 11.04 with both a Nvidia and an integrated Intel AGP in my laptop.
I am using an external monitor connected through a mini DisplayPort wired to the Intel card. It has been working since I installed Ubuntu 11.04 a month a go, today the external monitor stopped responding:
After double checking the cables, connections and the external monitor I booted back in the previous Kernel (I suppose yesterday I got an kernel update) and the external monitor came back to life. I did the test forth an back a couple times and the behavior was consistent.
The offending Kernel is 2.6.38-11-generic.
Last known good Kernel is 2.6.38-10-generic.
So far I am sticking to the previous Kernel while using an external monitor.
Following are my graphics device info:
As a workaround to be able to continue work, look here
Transcript:
You need to go to a tty shell (with no ui) by using, for example, ctrl+alt+F2. In the tty shell, you need to login and find any compiz process, using the command
Then, kill all the compiz processes:
Then run unity to initialize the UI:
Give it a moment to load and go back to the 'UI shell', using ctrl+alt+F8, to see the UI being initialized.
I had this problem with a DVI monitor plugged into a dock, using Ubuntu 11.10. I solved it by deleting the file
~/.config/monitors.xml