My initial troubleshooting of the problem was correct. The transmitter unit was defective. However, with my limited German skills and the kind assistance of the UPC agent I was able to order a new replacement unit. It arrived a few days later. Installation was quite easy and once completed the Wifi booster was again operating properly. My only remaining question is, am I required to send the defective unit back to UPC? There was no information telling me this was necessary but I also do not want to get charged for having two devices.