strong signal from one sat rv tripod setup -no channels

I have a RV tripod setup for a Phase III Satellite Dish (3 lnb 18x20). I have pointed this thing succesfully a few times during travels. This time it was a no go. I checked all my positions. They are right. I have one of those dish pointer hand held things.. it's getting a strong signal..

When I go to the satellite setup menu and check the satellite strength. I get 90 + from one of the 3 satellites. The others get zero. I thought It might be the LNB. SO i got another from ebay... I'm still getting the same thing. (i satellite with good signal 2 with no signal and no programming). I have done all I know to do.. other than swap the coax cable. It looks fine.

Anyone got any ideas?

I appreciate your time.