Panasonic TX-W28R4 AV problem, Help!

Hello!

I've had the tv for 2 years now and when I first bought it (ex-rental) all the av channels worked fine.

I first started using the av3 s-video connection at the front with my xbox and after a few months found that it stopped working, all i can get is interrupted non-sensical lines...

I then took to using a few adapters to use the av1 scart connection, after a while this also stopped working, a case of, it was working last time I turned it off, how come it has stopped working...

I then started using av2 (second scart connection) until last week this was functioning okay as well... if I try and use the av2 i get non-sensical lines at best... and it doesn't seem to be a lose connection since I have quite a few different bits of equipment and none work properly, the audio channels seem fine but the video side of things no longer works...

Could this be a chip problem? Is this worth me trying to fix myself? Or should i just buy a new Television ?

Any help appreciated!