2 out of 3 mini boxes don't work

I ordered 3 boxes and my son hooked up the one in his bedroom after having to call the help line. They said they were not turned on yet. His is working now.

2 days later I tried to install the other 2 boxes in the remaining bedrooms and keep getting an error that there is a problem with the box and to unplug/disconnect and try again. I have done this 5 times. Even after calling the help line I was told that it has to be something wrong with my house. Both TVs work fine if they are just using the coax cable from the wall. I also have a TV using the DVR box that works great. So how can there be something wrong with my house? I now have to wait for a service technician to come out next week.