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Since I updated to 11.04 my Computer seems to restart randomly. The screen goes black, sometimes it comes back If I move the mouse or press a key on the keyboard (but maybe that was just coincidence) but most of the time the screen stays black for about 15 seconds and after that I see the spash screen of my BIOS and the computer is restarting.

It seems to only happen when I am not using the computer directly (manipulating mouse or keyboard). So most of the time I will come back to the computer and it will just present the login-screen or the screen will go black while I am watching a video, listening to music etc.

I am using Ubuntu Classic without effects with the proprietary nVidia drivers.

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Just saw there is a "stackoverflow" for ubuntu :-> – Plankalkül May 21 '11 at 15:00
Flag your post (with the link under the "ubuntu-11.04" tag and ask a mod to move it if you want. I think Ubuntu questions are still considered on topic here, though. – jonsca May 21 '11 at 15:36
Don't bother moving the post. Sounds a lot like a hardware problem, which is on-topic here. – Turbo J May 21 '11 at 17:16
Some Addition: It seems to happen when the CPU is doing a lot of work and I am not moving the mouse or typing on the keyboard. So it does sound a bit like a heat problem although I am not sure if that is the whole story. Think I will test it out while letting a little script write temperature information to a file. – Plankalkül May 24 '11 at 21:06

You are going to want to check the logs to see if you can figure out what is happening.

Log files are stored in /var/log

The first log I would look in would be kern.log.

Also, I don't want to discourage you from asking here, but you would probably get a better answer asking on the ubuntu forums.

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Seems like it might be overheating. If so, kern.log will likely have messages like "CPU thermal limit exceeded". – Mechanical snail Aug 18 '11 at 19:49
Good information thank you! – Giovanni Azua Sep 27 '13 at 8:35

While you problem sound like hardware (check cables and connectors!) I have another wild guess: Screen saver.

Ubuntu ships 3D screensavers, and sometimes they can youse problems with the GFX card in 3D mode. Try to set the screen saver to "blank screen".

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