# Solved: computer shuts down on its own



## Iaife (Oct 9, 2006)

hi! my first post. if this is in the wrong forum for my particular problem, please feel free to move it.

my desktop is about 4 years old. a friend had built it himself, but was no longer using it about 2 years ago.

i have an ABIT BW7-RAID motherboard:

http://www.abit-usa.com/products/mb/techspec.php?categories=1&model=73

i have a gigabyte of RAM...a Seagate SCSI HD...among other things.

i got home one night (may be 3 weeks ago) & discovered that there was a power outtage. the desktop was completely shut down. my desktop is connected to a surge protector, but who knows...may be a power surge got to it. i hit the power button & the machine booted up fine.

anyways...about a week later, i came home to find the desktop completely shut down. there were no signs of another power outtage. i turned the desktop back on...but it had shut itself off again in the middle of the night. and that's when all the trouble started.

the next morning...and ever since then...i keep having to hit the power button multiple times (anywhere b/n once to over a dozen times) before the desktop would boot up properly.

usually, the machine shuts itself down completely w/in 5 seconds after i hit the power button to turn it back on. no weird beeping patterns on the initial boot up.

at first, i thought it was a PSU problem. i went out & got a new PSU...a MasterPower 350WATT ATX from CompUSA. unfortunately, the new PSU didn't solve the problem. exact same problem (shutting down completely w/in 5 seconds) kept happening.

i've since shoved the old PSU back in & returned the new one. i also got a can of compressed air & "dusted" out the dust bunnies (a suggestion i saw in another thread). the computer actually booted up properly after i "dusted" out the insides (this was after about a dozen failed attempts), but it then shut itself off about 12 hours later.

i've also tugged on the wires & boards after the computer boots up properly, but can't seem to get it to shut down while doing that (another suggestion from another thread).

lately, i've been messing w/it more. before, the desktop would stay on (after repeated button pushings) for about 12 hours before it would shut itself down. but now...it will stay on for maybe 10 minutes or so...sometimes 30 if i'm lucky.

most of the time, any folders or applications i have open would simply close & the computer would simply shut down completely. i have seen it...hmm..."properly" shut itself down (for lack of better words) twice.

one time, the computer got to the log in screen during boot up...when suddenly, it said "windows is shutting down". i stared at the screen & a few seconds later, the computer had shut itself down.

another time, i was chatting on WoW...when suddenly WoW closed & the computer said "windows is shutting down"...a few seconds later, fall down & go boom.

i tried looking for damaged capacitors (another suggestion i saw in yet another thread). i haven't had time to yank everything out so as to look more thoroughly, however. i will try that next week after my research paper is done.

hmm...what else...oh! under CMOS setup, (not sure of the exact wording here) the CPU heat warning, CPU heat shutdown, and CPU fan warning were all already "disabled." all my fans are working, by the way (including the CPU fan). i even put more...what's it called...CPU grease (?) on the CPU/heatsink (i was grasping at straws...hehe). but the problem persists.

well...i know how to put computers together (an amateur at it, though)...but i am not very good at troubleshooting hardware. oh, i don't know if it matters...but a while back, i was having problems & it turned out to be a bad RAM chip (used MEMTEST to isolate the problem back then). i've since replaced that bad RAM chip.

anyways...i was wondering if anyone might have an idea as to what is wrong?

thank you so much in advance...and sorry for the long post.

=)

Iaife


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## Rollin' Rog (Dec 9, 2000)

Have you actually tried monitoring the temps when it does boot?

http://www.almico.com/speedfan.php

How about testing the ram again?

Will it stay up longer in Safe Mode or Safe Mode with Networking support?


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## the_mad_hatta (Oct 9, 2006)

It's probably the power button on the front of the case that's got something to do with it. Or the pins for the power button on the motherboard. Try pulling out the wires for the power button and putting them back on the pins. It may fix it.


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## Bartender (Apr 27, 2006)

I agree w/ Rog -
You need to get a handle on voltages and temps. Speedfan will help with both.
Another idea that may sound kinda crazy - can you get ahold of a Linux CD, like Ubuntu or PCLinuxOS or SimplyMepis? Run it in the "Live" mode, where it runs from the CD without making any changes to your hard drive. Don't worry, it won't hurt your Windows PC!

If you bring up the Live CD and it runs OK then that's a pretty good indication that the problem is within Windows. If it crashes running the Linux CD in "Live" mode then the problem looks like hardware. Do you have a genuine Windows CD so you could run the Repair Mode thing? 

Adding more thermal compound isn't usually the best idea - better off to clean the old with some 99% pure alcohol, then re-apply a small dab. You want just enough to fill in the tiny imperfections between CPU and heatsink, not enuf to create an insulating blanket. 

I've never heard of a Master Power - for about the same money you could buy an Antec or Seasonic or Fortron


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## Iaife (Oct 9, 2006)

thank you everyone for your suggestions!

i will try them all and report back. i most likely will not get a chance to do so until next week...this research paper is *killing* me! lol

good thing i have a laptop i can write the paper with...hehe

thank you all again

=)

iaife


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## Rich-M (May 3, 2006)

I would just bet your Comp Usa psu was real junk and you have a failing psu. I would get a decent 400 watt psu because that sounds like the problem. Only ones to buy are probably what they don't carry which would be Antec, Thermaltake, Enermax and I would just bet that will solve this problem.


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## pshnfry (Sep 18, 2005)

What's the operating system, and what service pack? And are you running antivirus (type?), firewall, any other security apps? Is this pc connected to an always on internet connection?


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## Iaife (Oct 9, 2006)

hi! i *completely* forgot to mention something...not sure if it matters or not.

but...if i leave the power cord connected to the desktop, sometimes the desktop will power up on its own...and die out w/in 5 seconds after that. its happened on a few occasions. i have yet to see it properly power up on its own (make it all the way to the log in screen, i mean). i now leave the desktop unplugged. but before, it would sometimes try to power up on its own a few times in a row (like less than 1 minute after each of its attempts). and sometimes, ten mintutes will go by before it tries to power up on its own again.

Pshnfry: i am running WindowsXP...SP2 (latest). i do have McAfee Anti-Virus & Firewall & update them on a daily basis. and the desktop is connected to a router, which is connected to my cable modem. so ya, it is connected to an always on internet connection.

Rich-M: i will give your suggestion a try also when i get the chance. the PSU i got from CompUSA is:

http://www.compusa.com/products/pro...33067&Pn=MasterPower_350Watt_ATX_Power_Supply

thanks again for replies. i will keep you all informed. back to homework...*blech*

=)

iaife


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## the_mad_hatta (Oct 9, 2006)

Have you tried doing what I said? Unplugging the power button and plugging it back in?


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## Rich-M (May 3, 2006)

Well that story tells you it's the power supply...
That one is made specifically for Comp Usa and here is the real retail:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280020445631&category=42021
I have also seen them for $9.95 on eBay Express as well, that's why I don't shop
the" high priced spread" (to you brick & mortar Worst Buy, Short Circuit City etc....)


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## crjdriver (Jan 2, 2001)

the_mad_hatta said:


> Have you tried doing what I said? Unplugging the power button and plugging it back in?


This is not going to accomplish anything. All the power button does is momentarily close a circuit that supplies power to the board. Once the power is supplied [the system begins to boot] the power button does nothing. You can pull the wires off and it will still run.


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## crjdriver (Jan 2, 2001)

I agree it does sound like a power supply problem. I would test with a known good ps OR get an antec, enermax, sparkle, etc and install that.

One other possibility that has not been mentioned; that board was mfg around the time of the bad cap issue. Open the case and give it a very close inspection with a bright light. See if you find any leaking, discolored, or bulging caps.


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## Rollin' Rog (Dec 9, 2000)

I wouldn't rule out the power button if, when it shuts down unexpectedly, you see the message "windows is shutting down".

That's a "normal" shutdown initiated by a power button depress IF in Power Options > Advanced you have selected "shutdown" as the option for the Power Button.


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## the_mad_hatta (Oct 9, 2006)

crjdriver said:


> This is not going to accomplish anything. All the power button does is momentarily close a circuit that supplies power to the board. Once the power is supplied [the system begins to boot] the power button does nothing. You can pull the wires off and it will still run.


All the power button does is connect the two pins together. As Rollin'Rog above said, the Power Button does initiate a shut down in windows if that option is selected in the Power Options in the Control Panel. It also does turn off the computer while it's booting up if the Power Button is pressed. So I wouldn't rule out the power button.


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## Iaife (Oct 9, 2006)

hi everyone!

sorry for the belated update...school's been kicking my butt lately =(

anyways, i got a chance to mess w/my desktop yesterday morning & i think i've isolated the problem...here's what happened:

after having read all the suggestions, i decided to give the power button suggestion a try first...i do have my desktop setup so that the power button initiates a shutdown (which was why i decided try the power button idea first)

i yanked the front cover off...the wires connected to the power button were covered w/dust bunnies, but otherwise seemed fine...so i disconnected the wires from the motherboard & reconnected them

making sure the wires were firmly connected to the motherboard, i booted up the computer...at first, something strange happened. it seemed like the computer got power for like a tenth of a second, then *poof*...nothing happened. i hit the power button again, and nothing. i hit the master switch on the back of the computer, turned the master switch back on, hit the power button...and the computer booted up fine...but only to fall down & go boom w/in 20 mintutes

curious...i hit the power button again...this time, as the computer was booting up, i yanked the power button wires from the motherboard. well...the computer has been fine ever since. it has been running for a little over 24 hours now...not one single crash or shutdown. i have yet to reconnect the power button wires to the motherboard. i'm not sure if i should do that while the computer is running or not.

but anyways...the problem appears to be the power button (or the wires leading from the power button to the motherboard...or may be even the pins on the motherboard?).

at least i now know what the problem is...for the most part. i'll have to maybe get a new power button or something. but that will have to wait 'til later...graduate school = no time & constantly broke...LOL

well...thank you everyone for your replies & help. i do greatly appreciate it!

i like this site...very helpful info...and i hope to contribute some solutions

thanks again!

=)

iaife


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## crjdriver (Jan 2, 2001)

A quick test would be to connect the reset button to the power pins on the mb. Use the reset button to start the system [does the same thing as the power button] If it does the same thing, it is not the power button and would point at a problem on the board.


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## Rich-M (May 3, 2006)

Wow awesome idea crj!!!


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## crjdriver (Jan 2, 2001)

Yeah they really do the same thing and it is a quick and dirty way to check if in fact the button is bad.


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## Iaife (Oct 9, 2006)

hi there!

just a quick update...i tried your idea, Crj (great idea, btw...i never thought of it =).

plugged the reset button's wire into the motherboard...where the power button's wires go. the desktop booted up fine & has been running smoothly for hours now.

sooo...guess it was definitely the power button.

i'm sooo glad the problem's been solved now...i *never* would've guessed that it was power button.

thanks again, everyone!

=)

iaife


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## crjdriver (Jan 2, 2001)

You might try a shop that builds systems. They may have a power switch that fits you case. If you cannot find one, you might have to get a new case OR just use the reset switch to power the system.


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## the_mad_hatta (Oct 9, 2006)

You're welcome by the way!


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