Switching

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

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

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

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?

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

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

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

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?

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

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

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.

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

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?

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

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