missing some channels on dish 500

[maw1571]

I have a dish 500 getting signal between 100 and 105 on most transponders
dut some no sig at all.some time i get only 5 ppv chanels then the next day
i get 20 or so does anyone have an idea of what is going on

[RiseStar]

Very likely your dish is slightly out of adjustment and only picking up the left or right polarized transponders. It is also possible that you simply have a bad connection on your coax, either on the LNBF side or receiver side. The last possibility is a faulty LNBF, which is possible if you had the receiver powered up when you disconnected and reconnected the coax to the dish as it is possible to short them out in this fashion