how to tune satellite to desired position.

[twol]

in east London. they was working before but when the premiership started this season they went blank. then when I scan it, they would not come up, even when I add the freqenucies manually I get channel not found. so I its either my dish needs to set again by a satellite meter or reader wot ever they are called, or maybe a fresh new flash

As someone who lives in a marginal reception area, at various times of the year a weak signal mqy be picked up without problem but later not receivable.
The correct Dish size is the only thing that helps.