Have dish receiver 510, channels i need are on

Donna,
I am sorry to hear of your troubles. I am assuming you have another receiver in the house that is an HD receiver as the 510 is not and it would not make any sense for you to have the 129 orbital without it. If you go to the other receiver and are able to get transponder 21 on the 129 bird then the issue lies in either the cabling, connectors, barrels and or wall plate, or the 510 itself. Assuming you were good to go with the hi def receiver move it to the 510 location and see if you are able to still p/u the 21 transponder. If so, the 510 is bad and needs to be replaced. If not the problem lies in the aforementioned areas. if yoou are unable to get the 21 transponder on the hi def receiver also then more than likely the dish needs to be repeaked. If I can be of more assistance let me know. Thanks for using Fix Ya.