Encountered this problem with a new NCE Power Cab Starter Set. Resolved it with help from NCE. No need to return unit for service if you are soldering-capable.
Turned out to be some faulty soldered connections on the bottom of the Power Cab Panel. I found three pins that were bridged. (Heat up joint, then lightly tap it face down on table to remove off excess solder. Several other pins that were not soldered. Red LED of happiness is now aglow. [:)]