Computer turns on then off, then on again automatically

Computer turns on then off, then on again automatically
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Forums » Technical » Computer Hardware Help » Computer turns on then off, then on again automatically

fartness @ 2nd Sep 09:22AM:
Computer turns on then off, then on again automatically

I was surfing the web on my desktop that I built last year (specs will be posted if needed) and the computer froze. I still had my screen and everything but the mouse pointer froze and would not move and then my Logitech G15 keyboard's lights turned off.

I turned the computer off. I turned it back on then and it stayed on for two seconds, then shut off, stayed off for five seconds and then turned back on. Nothing to the monitor (no video) the whole time while this was happening. Never POSTed. I just hear the fans and everything going.

Ideas?

EDIT: I turned the PSU off for 20 minutes and plugged it into a different outlet. Unplugged keyboard and mouse. It now stays on but still does not post, rather than turning on, turning off, then turning back on.

After any time I unplug it and plug it back in for awhile, it will stay on but then when I turn it off manually and turn it back on, it will turn on, turnoff and then turn back on again automatically until I unplug it again.
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dragon @ 2nd Sep 12:27PM:
Re: Computer turns on then off, then on again automatically

said by fartness :

...(specs will be posted if needed) ...

they are possibly needed. problem may be the power supply, but there is a possibility that it may be other hardware... i.e.: motherboard.
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Camelot One @ 4th Sep 04:32PM:
Re: Computer turns on then off, then on again automatically

The power on, then off, then back on sounds like an Asus board. It should only happen once, each time power has been disconnected after a failed post. When it does that, it tries to post using the failsafe defaults, rather than any settings you've saved.

As for the problem, I'd lean towards bad memory, particularly if your board is an IGP. Remove all but one stick, unplug the power cord for 5 seconds, then connect and try booting. Repeat for each stick of ram, testing one at a time.
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Intel Q6600 @3400Mhz/GA-EP35-DS3P/2x 2048Mb G.Skill/Seagate 750.10/EVGA 8800GT's SLI/Silverstone 850W/Custom water cooler
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fartness @ 5th Sep 09:12AM:
Re: Computer turns on then off, then on again automatically

Wow, good call! Asus P5Q Pro and I just took one stick out and it booted. Will play around with it and see what the problem is.

EDIT: Weird how it booted with either stick tried alone. I'm running Memtest right now to see what is going on. I've also had it off and unplugged for a few days if that makes a difference.
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Camelot One @ 5th Sep 09:36AM:
Re: Computer turns on then off, then on again automatically

said by fartness :

Wow, good call! Asus P5Q Pro and I just took one stick out and it booted. Will play around with it and see what the problem is.

EDIT: Weird how it booted with either stick tried alone. I'm running Memtest right now to see what is going on. I've also had it off and unplugged for a few days if that makes a difference.

Being off a few days probably didn't make a difference, but disconnecting and reconnecting the power did. Other manufacturers have a sort of soft-reset bios option, if it fails to post and you hit the reset button, it will try with the defaults. The newer Asus boards require the power be disconnected to engage the default boot setting. (only requires long enough for the 5vSB to discharge)

As for both sticks working alone but not together, I've run into that with Asus boards (a lot), but its generally right from the start. If you had a working system and then it started doing this, I'd lean more towards one of the sticks having an issue.

In my P5Q-EM, I had the issue where I could get 4 2Gb sticks of memory to pass memtest checks all day long, but I'd get constant blue screens in Windows. The issue was the IGP, it pushed the memory in a way memtest wasn't testing. The solution was to bump up the NB voltage, and modify one of the less common memory timings (I think from 52 to 80), but I don't remember what the bios called it.
--
Intel Q6600 @3400Mhz/GA-EP35-DS3P/2x 2048Mb G.Skill/Seagate 750.10/EVGA 8800GT's SLI/Silverstone 850W/Custom water cooler
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fartness @ 5th Sep 09:39AM:
Re: Computer turns on then off, then on again automatically

The two sticks of 2GB ram have been in the computer since I built it (4GB total). I think I built it around November or December. It's always been rock solid and never any lockups or problems.

I ran Memtest on stick 1 and it passed. It's running on stick 2 and it looks like it will pass. Normally errors show up right away on Memtest but I will let each stick run about 10 minutes.

I will try different RAM slots too. If it boots with both sticks now, I will be stumped.
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fartness @ 5th Sep 10:34AM:
Re: Computer turns on then off, then on again automatically

Both sticks passed. Boots fine now with both sticks. I'm confused.
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mentormatt8 @ 29th Oct 08:14PM:
Re: Computer turns on then off, then on again automatically

This is quite an interesting situation. I see you have tried a lot of things and it seems that whatever you thought has fixed the problem, may not be the actual fix.

I had the same problem with an Acer Laptop and I found a solution here: »annoyances-resolved.blogspot.com···ing.html
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psafux @ 29th Oct 08:55PM:
Re: Computer turns on then off, then on again automatically

said by fartness :

Both sticks passed. Boots fine now with both sticks. I'm confused.

i would advise running memtest for a prolonged period of time. 8-12 hours (overnight perhaps).

I agree that memtest *usually* finds errors in the first pass but I have seen the occasional memory stick that won't fail for a long time.

Oh - and you can run memtest on both sticks at the same time. If it fails it will tell you at what megabyte it failed (1200 megabytes for example). The stick closest to the processor in 99% of systems is #1, so if you have 2 gig sticks, using the example of a fail @ 1200 megabytes, you can deduce stick #1 is the culprit.
--
Yes. the cat in my avatar is indeed mine.
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fartness @ 30th Oct 02:29PM:
Re: Computer turns on then off, then on again automatically

I'll try running it overnight. Works fine now, but I still want to know what caused this so it does not happen again and so there is no potential damage that could be done to the computer.
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Somnambul33t @ 31st Oct 10:25PM:
Re: Computer turns on then off, then on again automatically

unplugged it could have given the power supply or motherboard capacitors time to cool off. PSU could be bad or mobo could be dieing. you can have that problem when motherboard PWMs die.
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shinjuru @ 31st Oct 11:08PM:
Re: Computer turns on then off, then on again automatically

Reseating your memory probably fixed your issue. Perhaps slight oxidation at the points of contact?
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fartness @ 1st Nov 12:20PM:
Re: Computer turns on then off, then on again automatically

I always thought if it was a memory problem, the computer would just give POST beeps about the problem.
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shinjuru @ 1st Nov 06:56PM:
Re: Computer turns on then off, then on again automatically

POST Error Beeps are similar to the Check Engine Light of an automobile. Very rudimentary.
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