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I've got a friends computer that randomly goes into what seems to be a "sleep", but it doesn't respond to keyboard/mouse input. Like a bad little techie, I did absolutely no prior research, but instead jumped in head first trying fix after fix, which may not have helped anything.

Here's what I did (in order):

  1. Thinking it was on overheating issue, I tried to force the computer to overheat and shutoff using prime95, but after letting prime95 do its thing for 15 minutes, the computer didn't get past 62 degrees Celsius.

  2. memtest. Because I thought it was an overheat issue to begin with, it turned into a crapshoot from this point on. During the memtest, the computer screens went dark as if it went into a sleep mode, but the computer didn't respond to anything; keyboard, mouse, power button, nothing! So I did a forced restart, assuming that the computer crashed. It rebooted into windows "repair" mode.

  3. During repair mode it wanted to do a system restore, halfway through this, same thing. Screen goes into a sleep looking mode, with no response to keyboard, mouse, power button. Another forced restart!

  4. The computer reboots into windows, at which point it works for all of 2 minutes before it does it again.

  5. At this point I gave up and turned to google and Superuser for answers.

I did generated a reliability report, which just stated that the computer hadn't been properly shut down after each incident.

I'm stuck. Any help would be greatly appreciated.

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Does this happen if you run from a live-CD? – Renan May 12 '12 at 17:39
CRT monitor? LCD? Laptop? Desktop? Are the power settings configured to put the machine to sleep, or are they set to an Always On configuration and the machine seems to ignore this? Are the sleep based settings in the BIOS all disabled? Is the BIOS set to allow the machine to wake from sleep on keyboard/mouse? If it is an LCD display, it could be that the screen inverter that powers the backlight is failing, causing the display to go dark, while the machine is still running normally. – Bon Gart May 12 '12 at 18:43
It is a desktop running windows 7. Its a dual monitor lcd display and when they go dark, they both go dark simultaniously. The windows power settings are set to always on, but I didnt check the bios power settings. – Cygnus X May 12 '12 at 23:25

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