sounds more like a loose sat input or a short. unscrew the connector and check there is not a short on the lead (some copper wire from the outside shielding touching the hard copper core wire).
as far as i know i dont think you can use an amp on sats (i think i may be prooven wrong), sometime a dish can go out of alignment which can also cause pic break ups, or an LNB goes bad (you wont get any channels in this case).
but a bad connection sounds like the prob here