I'm going to jump in here with my recent experience. Last year we upgraded our Directv to the genie receivers. The main Genie DVR is set up for the living room and the mini was for the bedroom. Over the last year the main receiver has worked fairly well but the mini has been erratic, having issues connecting to the main receiver. A couple days ago, the mini just wouldn't connect at all. A call to tech service had me resetting receivers til I was blue in the face. I was convinced the genie mini was bad, they said it was the cabling. They finally set up a service call, I pay a small fee each month for insurance, so it was no extra charge.
Tech came out and went right to the UDC. I have a splitter there to get the signal to both locations. It was a 2GHz splitter with power pass, but it had been in there a year so he changed that. Then he pulled the connectors out of the UDC wall and replaced the barrel connectors on both plates. He then went inside and replaced all the barrel connectors to all the wall plates connected to the satellite cabling. When I asked him about that he stated that the barrels can "burn out" because they are not rated for the frequency that the SWM dish operates on. These barrels have an orange insert, while the cable and antenna connectors are white or black. He also said that even a static discharge can easily "burn out" those other connectors.
After all was done, both receivers work perfectly. And I was wrong about thinking the genie mini was bad.