Results 1 to 7 of 7
  1. #1
    New Lounger
    Join Date
    Dec 2009
    Location
    West Chester, OH, USA
    Posts
    4
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Newly built PC won't POST

    I just built a new PC with a new motherboard, new power supply, new memory, and an old CPU.

    Upon powering it on, the CPU fan runs, an LED on the motherboard lights (saying its in active state), but I get no POST. There are no beeps, and nothing at all appears on the screen.

    Initially, I didn't have the CPU fan fully seated (one mounting post wasn't fully inserted). This probably resulted in a small gap between the CPU and the fan.

    What I'm wondering is if that could have resulted in the CPU cooking to the point it no longer works. The other option would be that the new motherboard is DOA.

    My questions are:

    1) Could running the CPU w/o the fan correctly mounted cause it to fry?
    2) If so, how long would that take? I don't believe I ran it for more than 3 or 4 minutes at a time as I debugged different things.
    3) Am I correct in focusing on the motherboard and CPU, or could it be other components?
    4) Any hints/tips on how to test a motherboard and/or CPU? Without any test equipment I'm at a loss as to how to test (short of buying a new CPU and replacing the MB)

  2. #2
    New Lounger
    Join Date
    Feb 2011
    Posts
    4
    Thanks
    0
    Thanked 0 Times in 0 Posts
    1) Could running the CPU w/o the fan correctly mounted cause it to fry? - yes easily

    2) If so, how long would that take? - as little as a few seconds (the cpu gets to it's operating temps in seconds)

    3) Am I correct in focusing on the motherboard and CPU, or could it be other components? - Did it ever boot ? Have you got the four pin 12v connector plugged from the PSU into the motherboard ? ......unplug all ancillary components (hard drive/optical drive/floppy .....modems/any pci devices etc) and try booting it.......if it wont ......remove the motherboard from teh case and run it with just ONE ram stick on the bench (DONT do this on a metal bench lol).......basically you are then isolating it from teh possibility that it's somehow shorting out in the case...............if it does boot take a CLOSE look at the standouts and etc you have used to attach it to the case.....make sure nothing is shorting out


    4) Any hints/tips on how to test a motherboard and/or CPU? Without any test equipment I'm at a loss as to how to test (short of buying a new CPU and replacing the MB) - as above (its a process of elimination)

  3. #3
    New Lounger
    Join Date
    Dec 2009
    Location
    West Chester, OH, USA
    Posts
    4
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by drcspy View Post

    3) Am I correct in focusing on the motherboard and CPU, or could it be other components? - Did it ever boot ? Have you got the four pin 12v connector plugged from the PSU into the motherboard ? ......unplug all ancillary components (hard drive/optical drive/floppy .....modems/any pci devices etc) and try booting it.......if it wont ......remove the motherboard from teh case and run it with just ONE ram stick on the bench (DONT do this on a metal bench lol).......basically you are then isolating it from teh possibility that it's somehow shorting out in the case...............if it does boot take a CLOSE look at the standouts and etc you have used to attach it to the case.....make sure nothing is shorting out
    Thanks for the reply!

    It never booted.

    Yes, the four pin 12v connector is plugged in.

    I did remove all devices and cards - I'm using the built in video for debugging.

    Will bench the motherboard tonight to see if that helps.

    One thing I forgot to initially mention... I forgot to hook the power supply to my video card and did get a screech when I powered up. Plugging the power into the video card cured that. Not sure if this is of any importance or not - i.e. shows SOMETHING recognized the card needed plugging in - either the MB or the video card.

  4. #4
    Super Moderator CLiNT's Avatar
    Join Date
    Dec 2009
    Location
    California & Arizona
    Posts
    6,121
    Thanks
    160
    Thanked 609 Times in 557 Posts
    1) Could running the CPU w/o the fan correctly mounted cause it to fry?
    It's highly unlikely your CPU would be "fried" if one of your pushpins where not fully seated, you just won't be able to post. In most circumstances modern CPU's are built to tolerate and compensate for overheating and this includes poor contact. I've done the same thing you've done with no damage.
    3) Am I correct in focusing on the motherboard and CPU, or could it be other components?
    Yes. Go back to bare-bones set up; CPU and one stick of memory and a video card if you don't have on-board GPU support. Make sure your standoffs are appropriately in place and not causing shorts. Ensure everything is seated properly, including only the power cables needed for what you have on the mobo for the bare bones setup testing.
    Ensure that your CPU's heatsink and fan are mounted in the right direction.
    Getting a post with the absolute minimum amount of attached hardware is the goal to shoot for.
    Having the board outside the case when testing would be ideal.

    Don't forget that motherboards can and do come non functional, as well as memory and other components. It's a fact of life when doing your own builds. Test carefully and take appropriate electrostatic precautions.

    If all the above advice fails to effect a post (BIOS pre screen), consider an RMA on the board.
    Last edited by CLiNT; 2011-02-24 at 22:43.

  5. #5
    Silver Lounger Banyarola's Avatar
    Join Date
    Dec 2009
    Location
    Big Indian, New York
    Posts
    1,900
    Thanks
    19
    Thanked 65 Times in 54 Posts
    I had the same thing happen some time ago with a ASUS motherboard brand new and it turned out there was a hairline crack in the MB...

  6. #6
    New Lounger
    Join Date
    Dec 2009
    Location
    West Chester, OH, USA
    Posts
    4
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Thanks for the replies.

    A guy here at work mentioned that CPU's auto shutdown when overheated. Hopefully that is the case.

    Tomorrow, I'll take everyone's advice and bench the MB, remove everything but one stick of memory and give it another shot.

    I've already created an RMA for the MB just in case.

  7. #7
    5 Star Lounger chowur's Avatar
    Join Date
    Mar 2010
    Location
    Indiana
    Posts
    804
    Thanks
    0
    Thanked 54 Times in 51 Posts
    Just because something is NEW doesn't mean that it is working correctly.My point is it very well could be your power supply isn't running up to par.You can buy one really cheap here;http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH &Description=power+supply+tester&x=0&y=0
    Or you could check out your local Radio Shack.Also check the web site for the mother board memory compatibility.
    Problems cannot be solved by the same level of thinking that created them. -Albert Einsten

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •