Display falls into sleep after a bit of use in Unity but not in Unity 2D

[Francesco Fumanti]

When I write using dasher, which is set to normal mode, I often have the following: my display becomes black and the power button of my monitor flashes indicating that it is into sleep mode.

This only happens when I am using dasher in Unity; it does not happen in Unity 2D. Moreover, I was able to verify the problem in Ubuntu oneiric and in Ubuntu precise.

I don't know how to resurrect the display when it happens; even the alt-ctrl-f2 shortcut to switch to another console does not work. (It does however work before the display falls into sleep.)

My computer has a nvidia GT 240 graphic card and I am running the binary drivers from nvidia.

I suppose that it is an incompatibility between dasher and Unity, because until now, it only happened when running dasher; but I am not sure.

[Francesco Fumanti (frafu)]

In the meantime, it also happened while I was not running dasher; so it probably is not dasher's fault. Thus, I removed dasher from the "affected package" field.

Moreover, the problem also happened once in GNOME 3.

But, I never saw it in Unity 2D, though I have been using unity 2D quite a lot these last days to avoid the problem.

[Vadim Rutkovsky (roignac)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:

  apport-collect 898761

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Francesco Fumanti (frafu)]

It turned out, that the graphics card was shutting down because it got to hot. A proper flow of air was impeded because the holes of the tower were not completely free.