I almost did that same thing twice. When you are reaching around the back of a deep rack in a dimly lit area it is too easy to plug into the wrong jack because they are right next to each other. When possible now I flip the rack on its side to make connections before putting it on the stand and don't power up until I am sure it is correct.
Would the Axe still function properly if you clipped the connector off of an old Ethernet cable and kept it plugged in to avoid this possible disaster?
I just joined the club! Typical burning smell but Axe has been working fine for the last 5 hours.
Have any of you fellow club members who have not sent the unit in for repairs had any long term issues or are your Axe IIs working fine?
Doing this usually causes the MFC port to stop passing power. Otherwise, everything usually works fine.