A little behind upgrading but trying to upgrade to local channels on Dish 148. Have a 501 receiver and a Dish Pro Plus LNB which works fine for 110 and 119 but when hookup second dish with dual LNB and run check switch number #3 shows no connection. I know there is power to it as running thru a sat tuner. Is my DPP defective or am I using the wrong LNB for the second dish?