skybox f5 rubbish picture quality or no signal

my skybox f5 was working 100% up until 2 days ago.

now every channel including the FTA channels and jumping between perfeect picture/glitchy picture/no siginal and squeeling sound...............

this happens on ALL channels,

i dont have any other boxs in the house only this one, and its directly connected into my wifi.

aany ideas ? as this is unbearable to watch.............................