I have a Dish500 and VIP211k receiver that I use in my travel trailer. I don't have any problems aiming it (I've done it many times) but the last few trips I've found that when the dish is out in an exposed area (not shaded), that after the sun has shown directly on it for some time, my signal strengths have slowly weakened. Not a 'big' problem, but the last couple times, it's begun to reach the point that most, if not all, HD signals are too weak to view. I've checked my connections and have tried different cables and connectors. Could this possibly be a sign that my LNBf is going bad? Oh, btw, once the sun goes down, everything is 'back to normal'