Yep,,, I agree. I havent run across a bad lnb yet, but guess its possible. Would look more at the coax connections new to the system. Maybe test the voltage at the lnb connector to see if its what the power inserter is supposed to be putting out, then make sure the jumper coax from the power inserter to the receiver does not have a small short. Polorization is tilt. Measured from 0. Directv might label it, or number it differently.