Computer turns itself off! What do I replace (first)?

By streblo ¬∑ 27 replies
Dec 19, 2005
  1. Hi Gurus.
    Since several weeks ago, my desktop PC started to go off or restart itself for apparently no reason. Once it turns off, it doesn't go on again when I hit the power button UNLESS I turn off the main switch in the back for a while.
    Sometimes it does that after being on for many hours, or just a few seconds after turning on. Sometimes it just goes off (and remains dead until I do the off-on with the main switch), or sometimes it restarts again and again like crazy. It doesn't seem to have to do with OS (XP prof in this case) since the computer goes off even before booting up. Another tip: in some cases, when it ressucitates, the date was set back to 2003.
    Again, what is remarkable to me is that I have to put the main switch off for a while if I want to have any chance to get the computer up again. Otherwise it is completely dead.

    I think that the obvious choices are the psu or the mobo. But I don't know what to change first.

    Any idea on what could be wrong with my PC?

    Thanks a lot everyone.

    PSU: Powmax 350W
    mobo: PCChips M810DLU with integrated processor (AMD 1200MHz), video, sound and LAN.
    OS: XP professional
    HD: maxtor 30GB
  2. karusel

    karusel TS Rookie

    I had more the same thing going, one time it was the motherboard and the other time (which is exactly like your trouble), believe it or not - the system harddisk. The on-off went on for a while until by startup it said 'non system disk etc.'. If I were you, I'd really quickly make a backup, then try with another system disk, they're cheap these days anyway.
  3. nork

    nork TS Maniac Posts: 306

    I believe this is your power supply going bad. How old is it? To be honest with you, powmax is pretty much bottom of the line. See here:

    I am familiar with powmax and trust me, they just arent very good.
    Look at it this way, you buy a case with a power supply for, say, $40. Of that total price the power supply might be, say, $10 or $15. For that small amount of money you cant get a decent power supply. If you can get a powmax to run for a year or two you are doing well.
    You can get a decent power supply at places like for between $30 and $50, you dont have to pay more. And the power supplies that run for $15 and say they are 650 watts, stay away from them. These people twist the rules and basically lie about their power supplies. Best to stick with a good company, see the list in the link above.

    Best thing to do is to see if you can borrow a power supply from a buddy and hook it to your system to make sure that is the problem.
    It could also be a bad power on\off switch as well. Best way to test that is to take the 2 leads from the switch to the motherboard off. then take a flat
    screwdriver and place it against the 2 pins where you just took the leads off.
    If your pc starts up and runs fine then its the switch. But its likely the power supply in the first place.

    One thing you should check is your coin battery. These days you can get a new one for a dollar at the dollar stores. The battery should have a full 3 watts, if its less then you should install a new battery.

    While i do believe its likely your power supply you can use a setting in windows xp to give you an error message instead of turning off the pc, if indeed its a software issue, which i dont think it is, but worth checking out.
    right click on my computer, go to properties then to advanced then to startup and recovery settings, then see where it says "system failure" make sure there is no check under "automatically restart". Then save and exit out.
    This way, if there is a software issue you will find out.

    If you have a multimeter i can show you where to find a good tutorial to check the different outputs on your power supply to make sure its working right, but its easier to just try another power supply.
  4. Otmakus

    Otmakus TS Rookie Posts: 51

    Can u show us where to get to that tutorial nork? To be able to pick a better PSU next time I buy a PC.
  5. nork

    nork TS Maniac Posts: 306

    Sure i will, but i just want to make sure you understand that there are lists of good and bad power supplies and the tutorial i was talking about is a tutorial that will show you how to test your own power supply to see that each rail (line) is putting out the power it is supposed to be putting out.

    So, i will list a few places that list good and bad power supplies here:

    Now the tutorial, you have to go to I will go find the page and post it. You do have to sign up for free to be able to access the tutorial, but they wont bug you, its a very professional IT site.
    You do need either a digital or analog metre to test the lines (rails) of your power supply. They can be bought from hardware or big-box stores in the U.S. for about $10, the digital one is better, if i recall correctly. I have both so i forget which is better.
  6. nork

    nork TS Maniac Posts: 306

    I'm very sorry, but i have spent time there and i cant find it now. Its always been hard to find that darn tutorial. When i first found it i used screen capture and put it all in a wordpad doc so i would always have it.
    I will keep trying to find it.

    There are others, though, one can google for them.
  7. nork

    nork TS Maniac Posts: 306

  8. nork

    nork TS Maniac Posts: 306

  9. nork

    nork TS Maniac Posts: 306

    Just one more thing. I am pretty sure its your power supply, but there are other potential issues that could cause your problem.
    We have already discussed replacing or at least checking your coin battery for your bios.
    Here is one item we havent discussed, its the caps (capacitors). They can go bad. You can tell as they will bulge out at the top instead of being perfectly flat, or they will separate and\or leak at the bottom near the motherboard. You can go to for complete info and pics.
    Its not likely that you have bad caps but on the other hand, the mobo (motherboard) you have is an older pc chips and this particular motherboard, if i recall correctly, was prone to having bad caps. Now a lot of people dont like pc chips (ECS) mobos, but im not one of them. I feel they are very good mobos with a lot of goodies on them for a very low price. But others will disagree with me. It really doesnt matter, just giving you a bit of background as to why i am mentioning caps in the first place.
    There is also some info here on capacitors:

    I dont go to techrepublic all that much, but it found the item on caps while i was looking for the item on testing power supplies and i do know that mobo you have did have some instances of bad caps. Not suggesting yours has bad caps but you need to check. At this point this mobo is fairly old and you have gotten your monies worth out of it, i just hope we can get it back up and running for you.

    Some pc chips handle bios resets a bit different as well. I point this out because when you are having problems like you posted, the actual first thing to do is to reset the bios. But again, some pc chips boards do it a bit different, so you need to look up your manual. I can find one for you, i even have one around my stuff at home here. so if you cant find your manual let me know.
  10. streblo

    streblo TS Rookie Topic Starter

    Thanks for all the advises!
    So, this is what I'll do today, based on the recommendations I got so far:

    Make buckup in case of bad HD
    Change battery (the cheapest first!) and see.

    visual inspect at capacitors

    reset BIOS (I do have the manual, thanks nork) and see

    try a working psu (I borrowed one)

    I'll post what happened after this. Thanks guys
  11. nork

    nork TS Maniac Posts: 306

    i would say thats a good order you have there. Best to do backup first to make sure you dont lose any files you want.
    Once you install the other power supply, it would be good to test if you have a metre (multimeter), and it would be good to test the original power supply, but if you dont then run your pc hard. Open up big apps like office suite or run a cpu intensive game, things like that. Let the pc run overnight if you can. If it survives all that then you know the power supply is bad.

    To be fair and honest, if you have been using your pc for years with that powmax power supply, you have got your money out of it anyway.
    If you build your own pc like i do, then, in the future, dont buy a power supply that comes with a case that is real cheap. If its a good quality case with power supply, thats ok. What i do is i buy a cheap case and then i buy a very good power supply. If the case comes with its own power supply i sell it or give it away, or keep it as a spare.
    I didnt point out how much to spend as i believe you are from Europe somewhere? Just guessing.
    Hope all goes well. If not, we will help you out anyway.
    Let us know.
    Good luck.
  12. streblo

    streblo TS Rookie Topic Starter

    Well, I've replaced the batt but nope. All the same. I then replaced the psu and... voil√°! The PC started as a new one. It got the XP login screen fast as flash (much more than before). I'm goint to leave it on until tomorrow to check thoroughly, but apparently the problem was the old and poor powmax psu in agony. Is it OK that the computer goes faster now? or it is that it will blow up in any moment?

    BTW nork, I looked at the caps too, and it turns out that some of them (the big ones next to the heatsink are kind of booby at the top, and one of them even has a black hole (literally). Do you think I'll have to expect bad news from the mobo soon?

    Thanks a lot and I'll post if something else comes up.
  13. beerabuser30

    beerabuser30 TS Enthusiast Posts: 200

    The computer running faster won't cause a problem.
  14. nickc

    nickc TechSpot Paladin Posts: 923   +11

    won't but larger caps than expected could defenatly be the problem the solution to this problem as I see would be a new MB. I would say this is the problem.

    get A NEW MB

    just my opion
  15. streblo

    streblo TS Rookie Topic Starter

    My prblem, however, seems to have gone by replacing the psu. Those caps probably mean that I'll have to replace the mobo in the future, so I'll get a psu big enough to support an eventual newer mobo.

    am I right?
  16. dady393

    dady393 TS Rookie Posts: 17

    I had the same problem.

    pc shop found out that it was a default graphics card that changed shape while in use. Just try another card!
  17. nork

    nork TS Maniac Posts: 306

    Well, you replaced the power supply and all is well, so i was right.
    That means the vid card suggestion is not valid in your case. Doesnt make any sense as stated anyway. I have never seen a graphics card change its shape, must be stated incorrectly and mean something else.

    Now for the caps. If they are definitely not flat on top but have a bulge in the middle of the top then you are in for problems in the future.
    And, if one has a black hole in the top, then you can expect that motherboard (mobo) to die very soon.
    Maybe you should take it to a computer shop and just ask them to have a look at the caps for a second opinion. But if indeed you have a hole in one of the caps and others are rounded at the top, then the mobo will soon die.
    Unfortunately, this is a guarantee. It will run for some time like that then it will start freezing up and turning off and maybe not turn back on.
    But you have a new power supply to go toward building a new pc.

    You have a few ways to fix this situation:
    If you or a friend know how to solder then the caps are very very cheap to buy. I can show you where to get them on the net, but you can get them at places like radio shack.
    You can also have the guy at replace the bad ones, but im not sure how much that would cost, you can check with him via his email at
    You could find another used mobo that is the same as yours at this forum or another forum.
    You could research and find another mobo that will accept your current cpu and ram and get another mobo.
    You can buy or build a new one and sell off the parts from your old pc, except the mobo, you shouldnt sell that, it wouldnt be fair.
    Personally, i would either find the same or another mobo that would accept my cpu and ram or build a newer pc.
  18. nork

    nork TS Maniac Posts: 306

    I forgot, as for your old powmax power supply, they are very poor quality to begin with (see the list i supplied you with) so you have got your moneys worth out of it anyway.

    As for your pc running faster, as long as you have the right settings in your bios for your cpu and your cpu is listed as what it is supposed to be, then if your pc is running faster thats great. Just check and make sure. Its and AMD 1200 so just make sure its listed as that in your bios or in windows and if so you are fine.
    But, again, you still need a new mobo, based on what you have told us about the caps.
    To be honest, these mobos were known to develop bad caps, you are not alone, a lot of people have had the same problem with the M810.
  19. Calky

    Calky TS Rookie Posts: 22

    Hi if the computer keeps crashing then you should run through all your antivirus programs, I use AVG Pro, Ad-Aware Se pro, and spyware doctor, I also use a system registry cleaner called registry mechanic. After that go through your hard drive and remove anything you do not need anymore.

    Also go into my computers, right click on the hard drive and choose properties. Then run through disk clean up.
  20. nork

    nork TS Maniac Posts: 306

    Calky, generally speaking, your assessment would be correct. However, streblo stated:
    "Once it turns off, it doesn't go on again when I hit the power button UNLESS I turn off the main switch in the back for a while."
    If he has to turn the main switch off and on then its hardware, not virus.

    Also, streblo stated:

    "Another tip: in some cases, when it ressucitates, the date was set back to 2003." That also points to hardware.

    Plus, when you read his complaint and see he has an older 250 watt powmax power supply, that is a hint its a hardware problem.
    Plus, when streblo replaced the power supply and all is now well, it also points out the fact that it was a hardware problem.

    Its standard preventive medicine to do a disk cleanup, but virus-driven issues dont cause the problems listed above, they only cause freezing and rebooting issues, but they dont prevent a pc from booting and they dont cause one to have to turn the main switch on and off.

    But, checking for virus\malware\spyware is something a person should be doing all the time anyway, at least once a week. One should have an antivirus, and few different progs like m\soft antisyware, spybot, adaware, hijack this. Also, an online scan from places like are a must as well.
  21. Rage_3K_Moiz

    Rage_3K_Moiz Sith Lord Posts: 5,443   +38

    I'd suggest u buy this PSU
    Its high quality and has 2 fans, so no overheating problems. But its got a 4-pin connector so buy a mobo thats compatible otherwise try the others on that list nork gave u. Try to buy Antec coz they have really, really good PSU's. Good luck. And don't forget to check the connector on each of them.
  22. nork

    nork TS Maniac Posts: 306

    If you read post number 15 you will see he already replaced the power supply and the system is now booting up.
  23. Rage_3K_Moiz

    Rage_3K_Moiz Sith Lord Posts: 5,443   +38

    Whoops my mistake man. Guess I got a bit over-zealous. :p
  24. nork

    nork TS Maniac Posts: 306

    I shouldnt even have mentioned it as i have done the same thing many many times.
    But if i didnt then there might be another 10 posts about power supplies for this person when its already dealt with on the first page, lol. He already bought and installed a new unit and so we were right, he needed a new power supply.

    It was a good choice of power supply you made too! Too many people think you need like 600 watts.
    I run about 6 h drives, burner, 22 in monitor, but i only use onboard vid as im not a gamer, hence i dont need a $100 power supply. I only need a good quality 350 to 400 watt job, about $40 to $45 as you pointed out in your link, thats a perfect unit for the right person, like me.
    Not only that, but the mfgrs of the cheap junky power supplies are the same people who twist the truth or just lie and tell you its a really powerful 680 watt power supply when its a lie!! You gotta watch out for that too!
    Now some of the better mfgr do in fact have a ps that runs 600 watts or so, but you can tell by the price as it will be $100 and more!
    While on the subject, if anyone is going to build their own unit, buy a cheap case, take the power supply out and keep it as a spare or sell it, and buy yourself a separate, good quality power supply. Thats what i do. I dont mind a cheap case, but i DO mind and wont buy a cheap power supply. A good quality 300 to 400 watt enermax, antec, or other good make is the only way to go!
    Every day on forums like this there are dozens of people, just like this post, they have an old, newer, and even brand new junk power supply and their pc wont start.
    I would never buy a pc, i build my own, but if i did, i would order a new power supply and take out the ps thats in it. Unless, of course, the pc was from alienware or some other high-end dealer.
    Just last week a guy brought a pc in. It was an Acer, still under warranty. I suggested he take it back to the dealer for the warranty. What did he say to me? He said forget it, i would rather pay you than take it back and he told me a half dozen reasons. I checked the power supply, a piece of junk of course, the 12 volt line was down to 10 something, replaced the power supply and all is well.
    I would say that 25 to 30% of all pc probs are the power supply and i have read that too.
    rant over.
    Sorry to have corrected you.
  25. Rage_3K_Moiz

    Rage_3K_Moiz Sith Lord Posts: 5,443   +38

    Hey no bad blood and no damage done. Keep up the good work and Merry Christmas & A Happy New Year to u!
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