if they are normal smart strings...
are they connected to the ssc correctly? correct placement of the red, green, and blue wires? the wires on the side big chip running towards the ssc
are the wires on the far end isolated, and not touching each other or anything else that's conductive?
the port used on the hub... if you plugged another ssc in that place, and it works, then you didn't blow a fuse.