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Ask questions and share experiences about EX and QFX portfolios and all switching solutions across your data center, campus, and branch locations.
  • 1.  QFX5100 Not powering up

    Posted 04-14-2024 19:33

    During some maintenance on one of our racks it seems that the power cable to one of our QFX5100 switches came loose and may have been switching on/off rapidly for a some seconds before falling out of the socket completely. Now the switch does not power up. When power is applied it makes the starting sounds, fan start up but it stays there and doesn't boot into OS. Nothing shows up on console. Any advice on what to do



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    BRIAN LONGWE
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  • 2.  RE: QFX5100 Not powering up

    Posted 04-14-2024 19:44

    If you don't get any output on the console likely the internal drive was damaged too significantly in the multiple boot loops to work now.

    If you have an operational device, I would create a bootable usb using the snapshot command.

    request system snapshot media usb

    Then copy a new install file to the usb

    Then boot the down device from the usb 

    Then do a format install from the file which will reformat the internal drive in the process



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    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
    http://puluka.com/home
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  • 3.  RE: QFX5100 Not powering up

    Posted 21 days ago

    Hi, 

    Have tried this but the device is not getting to the point where it chooses to boot from usb. Fans keep spinning up then down continuously. Any thoughts?



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    BRIAN LONGWE
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  • 4.  RE: QFX5100 Not powering up

    Posted 21 days ago

    Another option would be to create a bootable USB from install media.  Then you need console access to interrupt the boot cycle at the loader screen and do the format install from this prompt.  The details are here.

    https://supportportal.juniper.net/s/article/EX4400-Format-Install-Procedure?language=en_US



    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
    http://puluka.com/home
    ------------------------------



  • 5.  RE: QFX5100 Not powering up

    Posted 21 days ago

    Thanks for the advice, unfortunately there is nothing displaying on the console at power up. So it is not possible to interruptthebootloader because the machine doesn't seem to be able to get past P.O.S.T.



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    BRIAN LONGWE
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  • 6.  RE: QFX5100 Not powering up

    Posted 13 days ago

    I'd say the switch is gone as you don't get any output at all. Do you have a spare PSU? If so, you can try with that. It may be that power is fed to some parts but not others, like if the 3.3 V is missing. Fans are 12 V I guess so they may work with 3.3 and 5 V missing. If you have another 5100 with dual PSU, you could borrow one from that switch. With the poor contact, the switching mode power supply had to work hard trying to provide power to the switch. Under voltage is more deadly than over voltage for them as the current increases with the drop in voltage and this causes components to fail (generic thing, not Juniper specific).

    I suppose you don't have a contract on this one, right?