Splatt_man,   Have you reviewed any of the logs, if so did you see anything reported? Are you seeing and errors, if so what specific errors are showing? If you have the logs available you can also upload them to upload. dell. com, and then private message me the svc tag you used to upload and I can retrieve and review them as well.   Let me know.    
I just started with my new company.  An issue we are having is we have multiple Dell n3048p switches that were working fine until a power outage occurred a week or so ago.  Now there are groups of ports that no longer light up.  They have cables plugged in and another tech attempted to plug his laptop directly into a few ports but nothing happened.  Any suggestions would be greatly appreciated.
Dell n3048p Ports not lighting up