Dish is a standard sky mini dish setup for 28.2
Installed by engineer a few years ago
Recently been having trouble with a few channels being very blocky and unwatchable
Channels affected are only on 2 transponders
And include bt sport hd epsn hd and the other transponder/frequency contain capital tv and heart music channels

I have a dreambox and a venton and both have issues on the same channels

I'm not sure if my dish has managed to move slightly over time or anything

I tried looking at the signal on the venton and dreambox but I don't really know what I'm looking at
On affected channels I'm getting snr reading of around 39% and 6.8db

Other unaffected channels show 55% and 16-20db respectively
Can somebody help me out and point me in the right direction

Thanks