Screen turns black when plugging in a second monitor

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:

• The external monitor reports no sync
• System > Preferences > Monitors reports the external monitor as attached and operational.
• Print Screen includes the image of the external monitor
• The laptop primary monitor works as expected.

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:

anibal@collar-de-bolas:~ $ lspci | grep -i VGA
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 Device 0df4 (rev a1)

anibal@collar-de-bolas:~ $ sudo lshw -C video
[sudo] password for anibal: 
  *-display               
       description: VGA compatible controller
       product: nVidia Corporation
       vendor: nVidia Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nouveau latency=0
       resources: irq:16 memory:f0000000-f0ffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:3000(size=128) memory:f1000000-f107ffff
  *-display
       description: VGA compatible controller
       product: 2nd Generation Core Processor Family Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 09
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:54 memory:f1400000-f17fffff memory:e0000000-efffffff ioport:4000(size=64)