I currently have 1 6100 and 3 4100 receivers. 2 of the 3 4100s and the 6100 work fine. This afternoon the reception on the other 4100 started to fade and now after multiple switch checks I don't get any signal to it at all. I moved that 4100 to another location and then it works fine. My guess is a failed port on the multi switch. Would this be correct? Also I am on an expired rental contract. Because I still rent all my receivers will Bell charge me for a service call? Thanks for any input.