PSU or Motherboard Problem?

Hi all, I'm sorry if there has been a post like this before, but I seem to have a problem and can't figure out if it's the power supply or motherboard. Just recently (this afternoon in fact) I started to run into problems starting up my computer. After some testing, I've come to the following conclusion: after letting my computer run for a few minutes and then turning it off, it will not start up again without being unplugged for about a minute first. There doesn't seem to be a burnt smell, and it runs fine aside from that problem.

Unfortunately, I'm not technical enough to repair the problem beyond replacing the problematic device, but I'm wondering if anyone can tell me if it's the power supply or the mother board that needs to be replaced? I'm guessing power supply, seeing as how the computer functions normally outside of the problem detailed above. I'm also wondering why it happens, but that's more out of curiosity than me being able to do something about it.

Thanks for any help!
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  1. Quote:
    Hi all, I'm sorry if there has been a post like this before, but I seem to have a problem and can't figure out if it's the power supply or motherboard. Just recently (this afternoon in fact) I started to run into problems starting up my computer. After some testing, I've come to the following conclusion: after letting my computer run for a few minutes and then turning it off, it will not start up again without being unplugged for about a minute first. There doesn't seem to be a burnt smell, and it runs fine aside from that problem.

    Unfortunately, I'm not technical enough to repair the problem beyond replacing the problematic device, but I'm wondering if anyone can tell me if it's the power supply or the mother board that needs to be replaced? I'm guessing power supply, seeing as how the computer functions normally outside of the problem detailed above. I'm also wondering why it happens, but that's more out of curiosity than me being able to do something about it.

    Thanks for any help!



    Strangely enough I have owned and still have a few machines that exhibit the same behavior yet they are still working.

    I never really looked into it in depth.

    I believe the PSU is certainly the prime suspect but I wouldn't completely rule out the motherboard either.

    What are your full specs by the way?

    That might help us determine what is going on.

    :-D
  2. Well, I'll probably pick up a new PSU sometime this week and find out if it's the problem, I'm just glad to know it's not likely to catch fire or something, so I don't have to rush off and buy a new one.

    Specs:
    Cooler Master Praetorian ATX Case
    Antec TrueBlue 2.0 480W PSU
    Asus A8N-SLI Motherboard
    AMD Athlon64 4000+
  3. Quote:
    Well, I'll probably pick up a new PSU sometime this week and find out if it's the problem, I'm just glad to know it's not likely to catch fire or something, so I don't have to rush off and buy a new one.

    Specs:
    Cooler Master Praetorian ATX Case
    Antec TrueBlue 2.0 480W PSU
    Asus A8N-SLI Motherboard
    AMD Athlon64 4000+



    You have really good parts and while it's possible the PSU or board may be going bad it might be something else.

    Are your outlets wired and grounded properly? Have you had severe weather or power disturbances recently?
  4. Nope, it hardly rains here, let alone thunderstorms, not to mention that I disconnect everything sensitive during storms. As far as I can tell, the wiring where I am seems fine, no power disturbances aside from some odd fluctuation that happened once about 4 months ago. This system has run for the last six months without problems, though I suppose the wiring could have degraded over time or due to some other problems. Still, if it were that, I'd think that it would cause my comp to lose power during operation, not before it even starts up. In any case, I'll probably pick up a new PSU to make sure, as it's a lot easier/cheaper than a new MoBo or calling an electrician to check the main line.
  5. Quote:
    Nope, it hardly rains here, let alone thunderstorms, not to mention that I disconnect everything sensitive during storms. As far as I can tell, the wiring where I am seems fine, no power disturbances aside from some odd fluctuation that happened once about 4 months ago. This system has run for the last six months without problems, though I suppose the wiring could have degraded over time or due to some other problems. Still, if it were that, I'd think that it would cause my comp to lose power during operation, not before it even starts up. In any case, I'll probably pick up a new PSU to make sure, as it's a lot easier/cheaper than a new MoBo or calling an electrician to check the main line.



    You can pickup a power supply tester for $10 - $20 from newegg if you're in the US...

    http://www.newegg.com/Product/ProductList.asp?DEPA=0&type=&Description=power+supply+tester&Submit=ENE&Ntk=all&N=0&minPrice=&maxPrice=&Go.x=0&Go.y=0

    Of course these are very basic... an inexpensive multimeter like one of these:

    http://froogle.google.com/froogle?q=digital+multimeter&btnG=Search+Froogle

    will give you much better measurements if you know how to use it

    and one of these:

    http://froogle.google.com/froogle_cluster?q=power+circuit+tester&pid=4900696283352957654&oid=17405317120329919318&btnG=Search+Froogle&scoring=mrd

    instead of having to pay an electrician 40-80 bux / hour
  6. linux_0 made some fine suggestions, and I just have a few things to add that may help to eliminate your mainline/wiring as a 'potential source' of your problem (no pun intended... right).

    Try to find a friend who doesn't mind your company for a bit and bring your pc over, try plugging into his wall sockets and see if it exibits the same behavior.

    If it does, ask him/her to let you borrow their power supply for a bit, install it into your machine and see if the problems persist.

    If they do, looks like you're down to the mobo's power handling circuitry my friend.

    Just my $.02
  7. Quote:
    linux_0 made some fine suggestions, and I just have a few things to add that may help to eliminate your mainline/wiring as a 'potential source' of your problem (no pun intended... right).

    Try to find a friend who doesn't mind your company for a bit and bring your pc over, try plugging into his wall sockets and see if it exibits the same behavior.

    If it does, ask him/her to let you borrow their power supply for a bit, install it into your machine and see if the problems persist.

    If they do, looks like you're down to the mobo's power handling circuitry my friend.

    Just my $.02



    Great idea :-D

    In fact if you put the two PCs side by side one bearing 0 degrees and one bearing 180 degrees you can usually run the power cords without ever removing the PSU from the case provided they are long enough.
  8. Thanks for the suggestions, but unfortunately I'm at least down to getting a second PSU, as pretty much all my friends use laptops. I've done a bit more checking, and there a few other symptoms I guess you could call them. For one thing, it seems that it's not that it won't start (at least initially), but that it'll start up for a few moments then immediately shut off, after that it won't start at all for a few seconds, then another false start. Also, it seems that the case speaker, which used to beep at me everytime I turn the power on, no longer seems to work, which may suggest MoBo, as that's what it's connected to.

    It also doesn't seem to be, at least, some major main power fault, as an older PC that I keep around as a backup doesn't suffer this problem at all (though, of course, its power source draws less power and may have different tolerances).

    I'm guessing (and I'm probably totally, totally wrong seeing as how my knowledge of electronics and circuitry is basically limited to installing computer components) that there's a short that occurs unless there's no or at least an insufficient initial charge to set it off, though again this begs the question of why nothing happens during operation (aside from the case speaker not working) and only blocks starting up without being unplugged first. Well, if it does turn out to be the main line, it's not that big of a deal seeing as how I'm moving in a few weeks.
  9. Quote:
    Thanks for the suggestions, but unfortunately I'm at least down to getting a second PSU, as pretty much all my friends use laptops. I've done a bit more checking, and there a few other symptoms I guess you could call them. For one thing, it seems that it's not that it won't start (at least initially), but that it'll start up for a few moments then immediately shut off, after that it won't start at all for a few seconds, then another false start. Also, it seems that the case speaker, which used to beep at me everytime I turn the power on, no longer seems to work, which may suggest MoBo, as that's what it's connected to.

    It also doesn't seem to be, at least, some major main power fault, as an older PC that I keep around as a backup doesn't suffer this problem at all (though, of course, its power source draws less power and may have different tolerances).

    I'm guessing (and I'm probably totally, totally wrong seeing as how my knowledge of electronics and circuitry is basically limited to installing computer components) that there's a short that occurs unless there's no or at least an insufficient initial charge to set it off, though again this begs the question of why nothing happens during operation (aside from the case speaker not working) and only blocks starting up without being unplugged first. Well, if it does turn out to be the main line, it's not that big of a deal seeing as how I'm moving in a few weeks.



    It might be a case of capacitor failure.

    http://en.wikipedia.org/wiki/Capacitor_plague



    Please take a very bright flashlight and check to see if any of your caps are leaking or bulging. Also check your entire machine for burn marks or strange smells.

    Caps and other components can fail in the PSU, on the board or both.
  10. Well, I'm backing up all my data right now on the off chance that when I try to replace the PSU I get one that fries the computer, so I can't really look to see if one of the capacitors popped, but there aren't any odd smells (I think, I've never bothered to smell my computer before), certainly no burning smells at least, though I'd think if something caught on fire inside my computer would probably stop working altogether. In any case, I'll give it a look over after I'm done backing up my data.
  11. Quote:
    Well, I'm backing up all my data right now on the off chance that when I try to replace the PSU I get one that fries the computer, so I can't really look to see if one of the capacitors popped, but there aren't any odd smells (I think, I've never bothered to smell my computer before), certainly no burning smells at least, though I'd think if something caught on fire inside my computer would probably stop working altogether. In any case, I'll give it a look over after I'm done backing up my data.



    Great idea, you can never have enough backups! :-D
  12. Truer words were never spoken.
  13. Well, after swapping out the old PSU for one of the same model, it seems that it was the problem. Preliminary testing seems to indicate the problem is gone, though I'll try again after leaving my computer on for a while just to make sure. As a side note, regardless of the old PSU being the cause of the problem, I don't think it's normal for the insides to look like a piece of white rubber was melted on top of several of the components.

    In any case, all of you have my gratitude for helping me out or at the very least taking the time to read about my computer woes.

    Edit: Hmm, don't seem to have the same problem, but there are significantly more fluctuations in the 12V range with the new PSU, which might be due to the fact that I altered the wiring setup to be a bit cleaner, as well as the fact that the PSU doesn't have an internal LED anymore. Well, the fluctuations don't seem to be causing problems, as they're still within 5% of 12V (it switches between 11.712V - 11.776V).
  14. Quote:
    Well, after swapping out the old PSU for one of the same model, it seems that it was the problem. Preliminary testing seems to indicate the problem is gone, though I'll try again after leaving my computer on for a while just to make sure. As a side note, regardless of the old PSU being the cause of the problem, I don't think it's normal for the insides to look like a piece of white rubber was melted on top of several of the components.

    In any case, all of you have my gratitude for helping me out or at the very least taking the time to read about my computer woes.

    Edit: Hmm, don't seem to have the same problem, but there are significantly more fluctuations in the 12V range with the new PSU, which might be due to the fact that I altered the wiring setup to be a bit cleaner, as well as the fact that the PSU doesn't have an internal LED anymore. Well, the fluctuations don't seem to be causing problems, as they're still within 5% of 12V (it switches between 11.712V - 11.776V).



    Actually that might be normal... sometimes they use silicone based glue or thermal paste on some of the components.

    Thermal paste / grease is sometimes white.

    If you could take a high-res pic we could probably tell you what it is.

    If there is strange stuff oozing out of your capacitors like the pic I posted earlier then that is not good.
  15. Heh, well, I know this might seem odd in this day and age, but I don't actually have a digital camera (or any camera outside of an instant one in case of a car accident). From what I can see though, and that's without opening up the PSU, it seems that white substance covers (and by cover, I mean it sits on top of them) quite a few things, several heatsinks, a couple capacitors, and some other stuff I have no name for (they look like copper wire coiled around pieces of metal).

    In any case, I've done some more tests and everything seems all right now.
  16. Quote:
    Heh, well, I know this might seem odd in this day and age, but I don't actually have a digital camera (or any camera outside of an instant one in case of a car accident). From what I can see though, and that's without opening up the PSU, it seems that white substance covers (and by cover, I mean it sits on top of them) quite a few things, several heatsinks, a couple capacitors, and some other stuff I have no name for (they look like copper wire coiled around pieces of metal).

    In any case, I've done some more tests and everything seems all right now.





    Sorry I couldn't find a better pic....

    If I'm not mistaken the white goo ( silicon based thermal paste / grease / heatsink compound ) in the pix looks like white rubber when it dries.

    I believe that's what you're referring to.

    If you can see yellowish gunk oozing out of your capacitors that is probably the cap failing, but if it's white or gray and rubbery looking it's probably sloppily applied heatsink compound.
  17. Sorry to double post



    The semi-translucent goo is silicon glue / hot glue ( indicated in white ).

    The failed capacitors are oozing yellowish / orangish goo ( indicated in red ).


    If you look closely under the dark power transistors secured against the large aluminum heatsink with a single screw each there is a gray thermal pad underneath each one. Before they started to use thermal pads, they used to apply tons of white heatsink compound sometimes very sloppily and it would get on all the other components if they overdid it.
  18. Well, then I guess that wasn't the problem then, though the new PSU seems to allow my comp to start normally. Oddly though, the voltage on this one keeps fluctuating, not anything major (except for a drop to 11.45V at one point) but not only does it seem to run at a lower voltage for the 12V rail (11.712 vs. 11.776), it fluctuates quite a bit compared to the relative stability of the old one. I'm guessing since I altered the wiring setup, more specifically I've placed all my media drives on a single cable, this may be normal.

    It strikes me as odd since I'm basically using the same model as the old one (Antec Truepower 2.0 480W vs Antec Trueblue 2.0 480W) yet the voltage readings are quite different.
  19. Quote:
    Well, then I guess that wasn't the problem then, though the new PSU seems to allow my comp to start normally. Oddly though, the voltage on this one keeps fluctuating, not anything major (except for a drop to 11.45V at one point) but not only does it seem to run at a lower voltage for the 12V rail (11.712 vs. 11.776), it fluctuates quite a bit compared to the relative stability of the old one. I'm guessing since I altered the wiring setup, more specifically I've placed all my media drives on a single cable, this may be normal.

    It strikes me as odd since I'm basically using the same model as the old one (Antec Truepower 2.0 480W vs Antec Trueblue 2.0 480W) yet the voltage readings are quite different.



    11.45V if that is indeed what you're getting is a little low.... but it's within 5% so that's good.

    As a general rule you want your voltage to be within +-10% of 12V DC.

    You could try to spead the load a bit by using different cables.

    But you should be ok.
  20. Yeah, I used to have them all on different cables before, but it ended up looking like a rat's nest in there with the various cables becoming tangled around each other. Still, I'll see how it goes, as I've disconnected the secondary drive, which houses all my backed up data (in addition to the other various backups on different media), so I'll run it for a week and see if there are any problems.
  21. Quote:
    Yeah, I used to have them all on different cables before, but it ended up looking like a rat's nest in there with the various cables becoming tangled around each other. Still, I'll see how it goes, as I've disconnected the secondary drive, which houses all my backed up data (in addition to the other various backups on different media), so I'll run it for a week and see if there are any problems.



    To test for stability and make sure everything works, I would suggest you memtest your system for 8-12 hours ( overnight )

    http://forumz.tomshardware.com/software/memtest86-ISO-burning-HOWTO-ftopict230767.html


    Or if you need to burn it under windows follow these instructions:

    Download

    http://memtest86.com/memtest86-3.2.iso.zip

    +

    http://isorecorder.alexfeinman.com/download/ISORecorderV2RC1.msi

    Unzip memtest86 and record the ISO to a CDR with ISORecorder ( you must have XP SP2 ).

    http://isorecorder.alexfeinman.com/HowTo.htm


    Also you could try running Knoppix and see if you have any stability issues.


    http://www.kernel.org/pub/dist/knoppix/KNOPPIX_V4.0.2CD-2005-09-23-EN.iso

    http://www.kernel.org/pub/dist/knoppix/knoppix-dvd/KNOPPIX_V4.0.2DVD-2005-09-23-EN.iso

    also prime95 should help test for stability too http://www.mersenne.org/freesoft.htm

    :-D
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