Crossposted from G&T:
So I woke up this morning and went to boot up my PC to check my email. I hear it come to life, then suddenly it turns off after maybe 3-4 seconds. Needless to say I was a little shocked so I tried again, same thing. Peeked into the side window and noticed that the CPU fan was not spinning, so I assume it's turning itself off as a precautionary measure.
I have noticed though that when I try to turn the computer on, it will keep trying to turn on after turning itself off - no idea what to make of this. So if I leave it alone after hitting the power button, it will run for 3-4 seconds, turn off, pause, turn on, 3-4 seconds, turn off, repeat. This goes on until I flip the switch on the power supply to break the cycle, but I've noticed that the fan will sometimes get a little 'shot' when I do this and will do a quick spin
Anyone have any idea whats going on? I'm in the computer lab between classes right now and really want to get back to my place to figure this out (wish I didn't find this until later so I wouldn't spend all day worrying) so I would really appreciate some of the forum's wise council in the meanwhile
Also if it helps at all the CPU is an E6750 with the stock fan, Antec 900 case, and the mobo is a Gigabyte P35
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If your fan was dead, no big deal. The computer should run until it overheats, then shut down. This should take at least a few minutes from a cold start, and at least 10-15 seconds if it was left running. So I don't think it's shutting down as a protective measure.
I really don't know why your computer would be stuck in a cycle of restarting and shutting off - maybe someone who's familiar with the mobo knows something, but if that's not a normal thing for it to be doing, I'd suggest looking more closely at the power supply or the board itself.
On a slightly unrelated note, my system has a different problem, whereby the video doesn't initialize at all 2 boots out of 3. I've confirmed this to be the case with two separate, known good PCI-E video cards, two different sticks of RAM, and the bare minimum of stuff plugged into the board (video card, one stick of RAM, CPU, keyboard). So that's an RMA. At this point, Gigabyte has been tentatively placed on The Great Big List of Mobo Manufacturers Whose Products VonPoon Will Not Purchase Ever Again.
As stated above many motherboards will shutdown after a few seconds if no fan rotation is detected.
You're absolutely right, it's shutting down to prevent serious heat damage. Well, either that or your power supply is bad (best case) or your power supply has overloaded and taken the motherboard with it (worst case).
Most likely this is a BIOS setting. Assuming that your PS and motherboard are fine it's probably a setting in the BIOS (I forget where) that says something like "Auto restart after error: enabled/disabled".
How to diagnose/fix it:
Find a computer buddy and take your computer to his/her place (or have them bring theirs to you, either way will work.)
Find another fan with the same type of power connector as your CPU fan, they usually look something like this. If the original CPU power connector looks like this, that's ok too because as you can see here, a three pin fan plug will still fit. For the record, make sure that the fan you find actually works, this is kinda important . Also, this is not going to replace your CPU fan so don't run out and buy a new one yet.
Now, take the fan you dug up and plug it into the power socket that your CPU fan is currently plugged into. Now, with your computer on its side, plug it in and turn on the power as normal. If the fan you just plugged in starts to spin then you're in business (Woo Hoo!). Don't let the computer stay on for more than a few seconds. If the testing fan spins then you know that your original CPU fan is dead and you should just run out to the local electronics store and buy a new one to install. Crisis averted.
However, if the testing fan doesn't spin then flip the power switch on the power supply and try plugging it into another power socket on the board and turn the machine on again. If it spins this time then you know that the power socket on the motherboard is dead. In this case you'll want to plug the CPU fan in somewhere else on the mainboard or get an adapter to run from the power supply to the CPU fan. If the computer will boot once you get this done (meaning that your motherboard isn't dead) then you're back in business. By the way, if this is the case it's usually a symptom of nasty things to come with your motherboard and you should go ahead and start looking into a replacement.
If neither of these things work then you've got bigger trouble. Here's where your friend's computer comes into play. First, send your friend off to the store to get some Coke or chips or something. After they've left take the power supply out of their computer ;-). Now unhook your power supply and hook your friend's up to your motherboard. No need to plug in all the drives and whatnot, just need to see if it'll post. Once you've got the motherboard power and 12v plugged in go ahead and try to turn it on (praying here helps too). If it posts then you just need a new power supply but, if it doesn't post still, you've got serious problems.
What you'll need to do then is to take everything off of your motherboard except the CPU and memory. Unplug all drive cables from the board. Take out all PCI devices and try it again. If it posts now then start hooking things back up one at a time until it stops working again. When this happens then you'll have your culprit. But if it still won't start then gank your friend's memory and try it with that. If it still doesn't work then you're pretty much screwed and will need a new motherboard/CPU. Sorry.
Hope this helped.
I had a gigabyte mobo, may have been the same p35-ds3r, but I wouldn't know I only had it for about 2 hours
Ran for a whole 20 seconds. Posted, then did the same thing in the OP
Mobo was Dead on arrival according ot tech support. Switched to my Asus p5b-E and I'm running smooth.
So I'm assuming the stock fan is just dying? I just built this thing like a month ago and have not had any problems besides this. Would it be a bad idea to let the computer keep idling so I can wait to see if/when it turns itself off, or would that just cause damage I don't need