Well you may have bought a refurbished 501 seeing they haven't been made in 5 years. A refurb could have come with problems but the fact the same problem is showing up you need to look elsewhere for the problem. Check out your cables seeing the superdish is also old and discontinued. The switch is probably your problem but seeing you didn't give much information about what you have that is only a guess. What are the results of a check switch test if it will run it?