No display when PC turns on. No POST beeps but all fans and drives run

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  1. Posts : 21,004
    Desk1 7 Home Prem / Desk2 10 Pro / Main lap Asus ROG 10 Pro 2 laptop Toshiba 7 Pro Asus P2520 7 & 10
       #11

    Hmm surprised Jimbos post didn't do something. maybe you have cooked the GPU and perhaps a few more things or even drawn too much from the PSU - correct volts does not mean correct current as I think I might have mentioned before.

    Think of it like a car with a battery that has 13.8v (normal) and does not have enough "charge" -amps (current) to crank the engine or if it does the current used by the starter motor sucks all the power leaving very little or none for the ignition system etc
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  2. Posts : 6,741
    W7 Pro x64 SP1 | W10 Pro IP x64 | W8.1 Pro x64 VM | Linux Mint VM
       #12

    Sounds to me like the motherboard's nailed.
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  3. Posts : 5,941
    Linux CENTOS 7 / various Windows OS'es and servers
       #13

    Hi there
    This is now about 99.99% certain that it's time for a new MOBO I'm afraid. If you can get the CPU checked somewhere else just to make certain it's not the CPU.

    Defective MOBOS are actually quite rare (with normal use) but they can break --especially when you do a lot of hardware changes --sometimes you can get microscopic breaks in the connections which are almost invisible to the naked eye.

    CPU's are hardier than you think unless they overheat --and had that happened I'm sure you would already have noticed.

    One final test -- sometimes you can get an invisible short circuit. Take the MOBO out of the case and place it on top of several sheets of newspaper on top of your (non metallic) desk - if you do it carefully you won't have to remove the CPU or PSU connections. Keep the POWER and RESET LED connectors connected and try again. Have everything else disconnected (except the Minitor of course) - including any of those USB2 connectors with 4 POST / STATUS lights on them if they exist and even the keyboard -- use Power on and RESET switch to attempt to boot as you won't have a keyboard for CTRL-ALT-DELETE or ESC or be able to enter BIOS commands. All we are trying is to get some sort of display from the BIOS.

    Note you often need to BOTH POWER ON and THEN Press the RESET switch when powering on the BIOS sometimes.

    If still no joy then you'll have to assume a broken MOBO or CPU -- your guess as to which but I'd probably suspect the MOBO.

    So time to get a new MOBO I'm afraid.

    Cheers
    jimbo
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  4. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #14

    You could also take the power supply to a small shop for testing. To me it smells like a power supply. The power supply you have is not one of quality.
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  5. Posts : 50
    Windows 7 Home Premium
    Thread Starter
       #15

    ICit2lol said:
    Hmm surprised Jimbos post didn't do something. maybe you have cooked the GPU and perhaps a few more things or even drawn too much from the PSU - correct volts does not mean correct current as I think I might have mentioned before.
    In regards to the GPU, I doubt it's fried. As mentioned in the original post, I have tested both the onboard, and aftermarket GPU's. As for the PSU, I borrowed one from a friend today and no change.

    Boozad said:
    Sounds to me like the motherboard's nailed.
    I suspect you're right.

    jimbo45 said:
    Hi there
    This is now about 99.99% certain that it's time for a new MOBO I'm afraid. If you can get the CPU checked somewhere else just to make certain it's not the CPU.

    One final test -- sometimes you can get an invisible short circuit. Take the MOBO out of the case and place it on top of several sheets of newspaper on top of your (non metallic) desk - if you do it carefully you won't have to remove the CPU or PSU connections.
    Indeed - if you read the original post, I mentioned breadboarding it.
    jimbo45 said:
    Note you often need to BOTH POWER ON and THEN Press the RESET switch when powering on the BIOS sometimes.

    If still no joy then you'll have to assume a broken MOBO or CPU -- your guess as to which but I'd probably suspect the MOBO.

    So time to get a new MOBO I'm afraid.

    Cheers
    jimbo
    Sounds about right to me. Thank you for your help.

    Layback Bear said:
    You could also take the power supply to a small shop for testing. To me it smells like a power supply. The power supply you have is not one of quality.
    PSU is fine. I borrowed one from a friend and it's doing the same thing. What makes you say it's not one of quality? I realize it's no Corsair, but I have yet to find a negative review of the company, or of their PSU's as a collective whole.
      My Computer


  6. Posts : 50
    Windows 7 Home Premium
    Thread Starter
       #16

    To all:
    Kindly read the original post before making suggestions. There have been several suggestions that I already tried and was clear about in the original post. Thank you. I am also an electrical engineering student, so I'm quite aware of the workings of certain components such as PSU's, etc, but in this malfunction, I'm at a loss. I've been building my own systems for over ten years. But I've never had this happen.
      My Computer


  7. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #17

    Think Tank I'm very sorry I did look up the wrong power supply. Ultra are rated very good and priced right.
    Please inform us what your next step is.
      My Computer


  8. Posts : 107
    Windows 7
       #18

    Corsair PSUs fail like everything else, I've just had an HX520 die after 6yrs. My bet is your BIOS is dead. It may be possible to coax it back into life, have a good read of the motherboard manual, but it probably means a new motherboard.
      My Computer


  9. Posts : 21,004
    Desk1 7 Home Prem / Desk2 10 Pro / Main lap Asus ROG 10 Pro 2 laptop Toshiba 7 Pro Asus P2520 7 & 10
       #19

    Think Tank said:
    To all:
    Kindly read the original post before making suggestions. There have been several suggestions that I already tried and was clear about in the original post. Thank you. I am also an electrical engineering student, so I'm quite aware of the workings of certain components such as PSU's, etc, but in this malfunction, I'm at a loss. I've been building my own systems for over ten years. But I've never had this happen.
    Yep we appreciate you have the knowledge mate but are just suggesting things as we are not assuming here we know any more than you.
    Now back to that PSU have you checked the Power_Good signal at pin 8 (grey cable) on the 24 pin plug when powering up see the reference to it in this link - page 2 (Voltage rails)
    Power Supply 101: A Reference Of Specifications - Power Supplies
      My Computer

  10.    #20

    Be aware that the thread, while useful, is over a year old.
      My Computer


 
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