EydieG,
I went through something (I think) is similar to what you're going through. I have an 05 DSDP and it had the older KVH stationary dome. I couldn't get mine to work either, I changed boxes and hooked up everyway I could think of, I even tried the box at home to make sure it was working. Calls to DirectTV didn't help, they had no idea. Then I took the RV to a local company and they figured out what was wrong in a few minutes. First the older dishes require a signal from the receiver. Now if your receiver is set up for home use (as mine was) it's probably set to SWM. You'd have to go into the set-up screen and change it for the receiver to send a signal to the dish. Then on the older dishes (as was stated earlier) don't automatically track the correct satellite. I had to press the search button on the dish until I got to the correct satellite, then it worked great. So bottom line make sure your receiver is set correctly or it will never work, then make sure you've focused on the correct sattelite. Hope this helps.