If there is an Admin password set on the switch, try using it. Also try using "Kenan" as the password.  Let us know if that works. 
I need  to erase the file system on our 5424 to remove the ssh keys, certificates, etc. When I try and use the Advanced option in the Boot menu (ctrl-shift-6) I get prompted for a password. What is this password? BobDehn 
PowerConnect 5424 erase file system