Since starting to use it, I've found that the Gamecube, 360 and Xbox all seem OK, as does the DVD player, but the PS2 has developed a fuzzy picture and a terrible humming noise under the sound.

I've tried a spare cable and the problem persists. I'd test it without the switcher but that would mean a massive rearranging of furniture to get at the back of the TV and I really can't face that

Is it likely the problem is the swithcer, bearing in mind that everything else plugged into it is fine?