I would download the latest firmware. www.dell.com/.../drivers Disconnect all other devices from the switch, and follow the XMODEM instructions that are included in the download to flash the firmware. 
Hello Everyone;  I have 2 switches (PowerConnect 6224) stacked together. Since we no longer need them stacked as we got new switches we decided to take the stack cables away and use them as individual switches. So I tried unstacking the switches first using via CLI but it did not work, simply nothing happens. So I took the stacking cards away from both switches and removed the stacking cables. Master switch works fine, but the slave keeps rebooting. I trued the following: From boot options, I tried reset, restore manufacture settings, format ... They look successful as the config seems like it's gone  and once the switch boots it ask me if I want to run configuration wizard but it will just freeze and reboot.  is there way to fix it? or the switch is dead?  All ideas are welcomed thank you 
Slave switch keeps rebooting after unstacking- Dell PowerConnect 6224