I have a two hopper one Joey setup and I've recently been unable to change the channel on the Joey. Unfortunately, all I get is a black screen when tuning to a new channel. I can power off the Joey and get the tuned channel to display a picture, but the screen goes black when trying to change it again. The only way to get the channel to display a picture is to power off the Joey. I've tried unlinking the Joey to no avail. Any suggestions?