First: No matter what any salesman may say: It absolutely should not do
this. (You'll see why this is important later in this post.)
Let's play a little game called Mastermind. Remember that game where
your mission is to find out what is the right color peg by eliminating
all of the others.
There are only four things in the signal path (Sat Dish, Box, cables
from box to TV, TV) . You've eliminated one for sure - the cables. And
if you've tried the component connections on another TV and found that
they work - that takes care of the box. (If you haven't tired this do
so.)
So we're left with the dish or the TV. But, since the dish had to be OK
for the box to be eliminated in the previous step - all that's left is
the TV. Have you tried the component inputs fed from a DVD? If not, try
that.
Go back to the store and have them try to duplicate it on one of their
sets. If they can't, write down the setting information and try to
duplicate those on your set. Or, restore the thing to the factory
defaults (my Samsung DLP can do this with in one step). .
Try googling it and see if others have experienced similar issues.
Otherwise (here's where my first sentence comes in) you may have to
pick a different set