After the install, we were experiencing a problem on the joeys when trying to join the other's programs with all four devices on (1 hopper, 3 joeys). 2 out of the 3 would work fine but on one it would always get a black screen. Channel info and everything would show up, but no picture. Tech originally thought it could have been the coax to the hopper because the wiring was existing and couldn't confirm it was 3Ghz. He noticed the wall plate and said he knew that it was only rated for 1.5Ghz and swapped it out to the blue barrel on the wall plate. After that the issue disappeared and no more black screen.