Troubleshooting simple dish

I have a simple 18 inch dish here. The signal level is about 90. The receiver test shows 'locked', every other transponder shows zero in the cable test. Consequently, the screen says 'Searching for satellite signal' on most of the channels. Those channels with a picture break up intermittently. So there appears to have been a system failure somewhere.

I unplugged the receiver over night to reset it and that didn't help. Maybe someone has seen this problem before. Any suggestions before I begin troubleshooting?

--- CHAS