The only function of the power inserter is to push voltage to the 4th sat input, and distribute the difference to the first port. It is not meant to be installed with less than four sat locations connected. Connecting it can cause reciever failure by over taxing the reciver tuners, the extra voltage has to go somewhere and if it isnt the switch it drops the power back off to the recievers. But let us be honest, with rampant incompatabilty of equipment and a million different home types and combinations of equipment, manufactured by a hundred different companies, installed by incompetent techs a lot of times. Ive seen equipment work for four years that absolutely should NOT have worked for one day, and perfect installations fail immediatly. So who really know.