1. Old Dish receivers are/were useful for i-slinker service. The i-slinger service is dead now for the past 3 month. 2. If you have a working FTA receiver connected to a DP34 switch and Dish LNBs, the power supply problem can be solved by using an old Dish receiver connected and on all the time. 3. Apart from these the only other use might be for getting true FTA signals but this not a very satisfactory exercise for novices.