You also have to hold the button in the search position for at least three seconds for it to begin it's search. Sorry I can't help you with Dish as I have Direct.
One other thing to check...make sure the phone cord is plugged into the box as well as into the KingDome. To check this, you'll have to remove the seven screws and remove the plastic cover. I would unplug it from both places, then plug them back in. There also should be a black, (ground) and a red (12VDC) wire attached to the KingDome box...that's the one you described... Make sure you have 12VDC and a good ground......Dennis