Possessed power button

Hey all.

So I'm fixing up a fairly POS computer with cannibalized parts and have run into an odd problem. The power button is possessed. Or maybe there is a short somewhere, but I'm convinced that it's actually possessed.

Everything on the computer works fine, I have Ubuntu loaded up and installed etc, so the hardware works. The issue is that the power button randomly decides to work or not. I can press the button ten times and then all of a sudden the computer comes on (occasionally not directly after the button press). I thought for a while that the PSU was shorting out on the case and sometimes when I have my hand touching the PSU casing and computer case, it'll turn on normally. Other times when I play with the unused wires, that makes the computer turn on. And still other times when I've unplugged the Power Button header cable it'll turn on while the header cable is being pulled. It's all very random and I haven't a clue what makes it work sometimes and not others.

Given enough messing around with the computer does eventually turn on but it would suck to have to fiddle for 5mins every time I wanted the computer to be on.

Thanks for any suggestions or ideas.
6 answers Last reply
More about possessed power button
  1. When working inside your computer it's always a good idea to unplug the PSU from the wallsocket. You may have fried something while working with a PSU under power.

    Since you say it's a pile of old parts it could be the board is dying on you.

    Check BIOS for any WAKE_ON_EVENT settings (mouse/usb is most likely).
    State after Power Loss might also be worth a check.
    If not test with another powerbutton (from a different case).
    Recheck other connections (reset, leds, speaker for stripped wires/shorts)
    Reset CMOS, flash BIOS.
  2. if the power button is messed, plug the reset button there, if it works then the button is screwed(you now have a reset power button). If its still the same you have another problem to trouble shoot.
  3. Cheap PSU's have issues with cold starts etc - could be one angle

    Wire the reset switch to the power header and use it for the time - see what that does

    You can use anything metal to start the system - just short the pins etc

    and yeah - power settings - disable wake on x etc
  4. Andrius said:

    Check BIOS for any WAKE_ON_EVENT settings (mouse/usb is most likely).

    This is fairly good bet.

    One is, change the cables Puld the reset button in the power pins and unplug the power button.
    Ive seen several Xoff Buttons working badly.
    Might be a PSU problem aswell.
  5. Hey all. Thanks for all the feedback. I tried swapping the reset button for the power button and the same issue remained. I also disabled all the power on options and nothing changed. I'm fairly certain that the PSU is on its very last legs.

    Oh, and I noticed something else odd. When I went into the PC Health menu I noticed and odd occurrence. Every time that the PSU fan made an odd fan squeak the voltages would blip momentarily. It'd squeak and the 12v would flash a change or it'd squeak and the 5v would blip a change. I would imagine seeing that happen is usually a bad sign :)
  6. It's either the motherboard or the PSU dying. Since the squeaks are comming out of the PSU it's more likely. But with the random starts the motherboard is not yet off the hook.
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