robz gets the cookie, you either have a short in one or more feeds and by short it could be a splitter in the line. Are you using a sat buddy and are you getting voltage all the way back to the Lnb? it is either a short in line a splitter in line or a bad lnb or multiswitch. these can be a pain to locate. i notice you said you replaced ALL cable and fittings? if you truly did, then the only two things it can be is a bad ird that is consumming more than 18v and thus interfering with the other irds in system when in operation or you have one or more bad outlets in home. looks like you'll need to invest in a volt meter for this one.