"Searching for signal" on 2 channels only
We have an older RCA receiver and dish (10 yrs). The system has worked fine until 3 weeks ago when it couldn't find The History Channel or the History Chan. International. It works fine on all the other Channels we are supposed to be getting (Total Choice Plus). In fact, you can be tuned in to one channel, switch to the Hist channel, the title is there but the screen is blank. After a pause, the searching for signal message comes up. If you switch to any other channel (except Hist Int), you have instant signal. What could be the problem?