I help volunteer at a HS theater. They currently use the Telex intercom system powered by a PS-1F . They are running 5 BP-1002 beltpack units and have been for 10 years. This week they could barely hear each other through the system but could hear themselves clearly in their own headset. I've checked for shorts and open circuits at each connector box and check each connecting cable but don't find any problem. I'm showing at least 24v at the power supply itself. I eliminated the house wiring by connecting a beltpack directly to the power supply and daisy chained another unit to the first, still could not clearly hear the other unit. The only common item is the power supply. Could this be failing under load from all units connected. Just trying to be sure before replacing a $400 power supply. Thanks for any suggestions.