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If my motherboard is dead will my power supply still turn on?

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  • Motherboards
  • Components
Last response: in Components
January 17, 2012 5:16:58 AM

I've been having some trouble with my PC build and I have narrowed it down to either a bad PSU or a bad/fried MOBO.

My question is:

If my motherboard is dead, will the fan on my power supply still turn?

Summary of Problems

  • Nothing seems to turn on or boot when I apply power to the PC

  • There are 2 small green LEDs that glow on my video card, even though nothing else works. Would this indicate that the PSU is working?

  • No fans turn on. Not the PSU fan or any of the case fans (even the ones that are plugged directly into the PSU and not connected to the MOBO

  • The PC booted fine the first time. Everything worked and I powered it down/un-plugged to do cable management. I wore an anti-static band the whole time, which was grounded to the case.
  • More about : motherboard dead power supply turn

    a b V Motherboard
    January 17, 2012 5:55:57 AM

    Yes your fan would still turn on, more then likely the board would power up and then sit there and do nothing.
    if nothing powers on at all change PSU's more then likely thats the culprit
    January 17, 2012 9:13:51 AM

    Thanks a TON. I've been scouring forums and checking/re-checking everything. I'm going to get a new PSU asap and try it out. Why do you think it powered on the first time and then died? Is that a common occurance?
    Related resources
    January 17, 2012 9:22:30 AM

    Rarely the PSU won't power up due to a faulty mobo. This is because the power button has to send a signal through the motherboard itself to signal the PSU to turn on. I'd try and test another PSU on the system if you have one available. Chances are the fan would turn on and idle, but it's best to double check that the power supply is getting the signal to turn on. :) 
    January 17, 2012 4:56:35 PM

    I installed a new PSU and it works. The original PSU was bad.

    Now the windows USB boot drive I made isn't working!! "No Device Drivers were found". I'm pretty sure the initial Windows 7 boot has to be from the DVD drive. I guess this means I have to spend more money and get a bunch of DVDs
    a c 95 V Motherboard
    a b ) Power supply
    January 17, 2012 6:46:48 PM

    Hi MrPickle

    almost all modern motherboards will boot from a USB memory device if the BIOS is set to boot from USB devices before CD drive & Hard Disks
    (Provided the USB device has been correctly prepared).
    [The USB device needs to be inserted before switching the PC on]

    Do you have another PC to test the USB device on.?
    Dell, Toshiba and many other motherboard have a F key you can press during start up to make a one time choice of boot device.

    My Intel motherboard has F8, Dells are usually F12
    [ read the motherboard manual, as sometimes the message is hidden (BIOS Option to show or hide boot messages)]


    Mike Barnes

    January 17, 2012 7:50:02 PM

    I had my HDD plugged into SATA3. It's SATA2.