My computer shutdowns itself, how can I diagnose it

desktop-computerpowerpower supplyshutdown

I have a 5 years old Dell XPS 8100.

A couple of days ago, it suddenly shutdown itself and then restarted again. Just like if there had been a power supply outage at home… except there wasn't one: the lights, TV, computer monitor… everything kept working, the only thing that shutdown was the PC. I know that computers are way more sensible to power supply variations than other electronic devices, but still, I'm afraid the problem is within the computer, not an external cause.

Yesterday, I had the PC running for at least 12 hours, with no problems at all. But today it has happened again.

Both times the PC had been up for just a few minutes before the shutdown, so I would discard any temperature related problem. All the fans are working properly, and surprisingly, there isn't much dust inside the PC.

Where could be the issue? External problems, power cord, power supply… motherboard? Anything else? How can I even begin to diagnose it? I don't have access to a compatible replacement power supply, which, I guess, it's the most likely culprit…


I forgot to mention, the PC was plugged into one of these things (I believe they are called surge protectors?). I have now removed it from there and plugged directly into the wall socket, just in case that was the issue. But no way to know, just wait and see if it happens again or not?


There isn't much useful in the event logs. A couple of Nvidia update services not responding… nothing unusual. The last three entries before the shutdown are:

11:05:32 - 7036 - Info: "Security Center" service is running.
11:06:06 - 7011 - Error: timeout (30000 ms) waiting for "ShellHWDetection" service.
11:08:03 - 7022 - Error: "Windows Update" service doesn't answer after starting.

And then after I restarted the PC (I'm copying only the relevant ones):

11:23:19 - 6008 - Error: Previous system shutdown at 11:08:36 was unexpected.
11:23:13 -   41 - Critical: The system was restarted without a clean shutdown. This error
                  may happen if the system stoped working, blocked itself or the power
                  supply was interrupted.

Then there is a quite weird one, 9 minutes after the restart…

01:00:00 -    1 - Info: System date was changed from ‎1999‎-‎12‎-‎31T23:59:59.999000000Z to
                  ‎2016‎-‎03‎-‎25T10:32:35.750232100Z.

Best Answer

I think you should check whether you are getting Blue Screen error. Open Control panel, then System and Security, then System, then in the left pane open Advanced system settings. Open Settings in the Startup and Recovery section. Uncheck "Automatically restart" option. Then OK everything. If it is a blue screen error, then it'll be shown the next time computer hangs.

Related Question