PC not turning at all, but sometimes randomly turning itself on?!

Hi guys, my aunty has a problem with her computer, when you press the power button nothing happens at all, the fans don't turn on, no beeps; it's completely dead. But apparently if you leave it on at the mains, it'll randomly turn itself on.

I've tried everything I can think of, taken out each part individually, disconnected everything and tried a PSU; all without any luck.

Is there anything else I can try, or should I just get a new motherboard for her?

14 answers Last reply
More about turning randomly turning
  1. How old is the machine, possibly it's dying :(
  2. Yes, but which part in particular? :P

    It's a good PC, it's not very new but at the time it was pretty much the best you could get I think, the case alone cost ~£200, and the PSU was decent too, ~£80 or so.

    Basically, buying a new PC isn't really an option :(
  3. It could be any number of things. If you tried a different PSU, next I'd try a different stick of RAM or could be the hdd but kind of doubt that. It's possible it's the board or CPU. Regardless how could the computer was at the time of purchase, things do wear out. Could you give the specs of the machine
  4. Really not sure of the specs I'm afraid, it's an AMD Athlon with 1GB RAM though if that helps, I think the graphics is a 6800 too.

    I've already tried it without the RAM and HDD plugged in so I don't think it's that, which leaves the board and processor! Maybe I should just buy a cheap bundle or something.
  5. Keep in mind if you buy a new mobo and CPU, you'll need new RAM given both AMD and Intel are now using DDR2 RAM and her current RAM will not fit these boards unless of course they are DDR2, which isn't likely. Also you'll likely need a new video card because most of the old boards don't have AGP slots, they use PCIe x16. If you have a tight budget, your best bet is AMD, just read they're reducing their prices again. In the US you can get an AMD AM2 X2 3800 CPU, mobo with onboard video, and a GB of RAM for less than $200. Make sure the board will fit in the case, most mobo with onboard video are micro ATX so this may not be a problem. The other thing is to make sure the PSU will work, e.g., Dell used to use a proprietary PSU, they still may, that couldn't be used with a standard mobo. You should definitely be able to use her old hdd and CD/DVD drive. If the machine is more than about 4 years old, would be a good idea to replace the hard drive, they all wear out eventually. You may be able to buy a very low budget, cheap, machine for almost the cost of building but building would give you a much better machine that will last her a lot longer. While I'm a true believer in building, if your budget is really tight and you just want something, buying has the advantage of all new parts and a copy of Windows but again it's not likely to last very long
  6. It might also be just malfunctioning power button, though that seems a bit unlikely. Test what happens when you manually 'hotwire' it.
  7. Is the machine OFF or is it in standby when this is occuring?

    I bet you have the NIC set to 'wake on command'
  8. Your PC is possessed, get a priest. As Kari said, "It might also be just malfunctioning power button" Try Shorting the pins on the mobo that the power button connects to. If that works you can swap the power button with the reset button. I have never heard of CPU, RAM graphics card, hard drive etc. powering up a mobo. could be that the mobo is asleep and the NIC is waking on LAN as per grieve. If you get it started turn off all standby and hibernate in both BIOS and XP. I'm leaning toward the power button or whacked mobo.
  9. Thank you so much for the replies guys! My current plan of action is:

    1) Reset the CMOS (I assume the NIC set to wake thing will be sorted then?)
    2) Use a screwdriver to short the power button (I did try doing that already tho, swapping the power and reset buttons around)
    3) Buy the exact same (or similar) motherboard from Ebay.

    I don't think getting a new mobo/cpu/memory/graphics is really an option unfortunately ;o
  10. I second the idea of resetting the BIOS to defaults. Use the jumper on the mobo to do it if possible.
  11. "But apparently if you leave it on at the mains, it'll randomly turn itself on."

    What exactually do you mean by this? Are you disconnecting the power cord or turning off the PSU switch?

    I ask because my company had some Compaq computers that if you did either of those you would have to wait for the system to power-up (anywhere from 30sec to 3 minutes) then it would turn on. My company had several that did this and worked fine so I believe it could have been by design. If you are disconnecting the power after each use, what happens if you leave the computer power connected and just do a shutdown? In other words can you do a shutdown and after it switches off you can turn it back on without issue, never having removed the power?
  12. Cheers again guys, I've tried both disconnecting the cord and turning off from the power switch, I left it on for bloody ages and it didn't boot up at all, I think it's a case of it turning on after a few hours rather than just seconds or minutes unfortunately.

    I'm looking through the manual now and it mentions something about USB wake-up device, is it even worth looking at that?

    Is there anything else really worth looking at other than resetting the CMOS and manually trying to turn it on by shorting the jumpers with a screwdriver? I'd hate to go there yet again and still not be able to order a new motherboard because there's something I still haven't tried! ;o
  13. First off, give us some more info on this machine *Specs*

    Try taking the thing out of the case and test it on a static safe surface. What could be happening is that you are getting a short somewhere due to the motherboard touching parts of metal of the case.

    Clean it of dust/debri, there might be small fragments of metal floating around in this thing. *or something else that can conduct electricity* This includes the board itself and all PCI and RAM slots.

    Just for the hell of it I would Flash your BIOS. *or at least check and see if there are any BIOS updates pertaining to this problem*

    Make sure you remove all uneccessary hardware *anything in the PCI chain, USB devices, only 1 stick of RAM, no Hard drives.*

    Pull the processor out, cheack and make sure all of its pins are intact, also make sure if it is a older Athlon chip *Socket A's XP's,Thunderbirds Durons etc etc.* make sure that thermal paste is ONLY ON THE DIE!!! I don't know how many times I've come across someones computer having problems and whoever put it together for them think its a P4 or something and covered the whole thing in goop. Goop/TIM is really problematic if its anywhere else other than the DIE.
  14. it is definitely worth looking at the usb wake up settings. If either that or the wake up on lan is enabeled, this might be what is bringing your computer on. If this is the case, you know that the mobo, cpu, and powersupply are good. this would lead you back to a faulty switch or something. Although, this just came to me, if there is a short on the motherboard around the pins where the switch and reset button are plugged in, then your mobo might be bad.
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