Ford focus dash display unit

The mile clock is gone in the unit, there is no digital display coming up, and the petrol and water needles jump when engine is off (just an annoyance). I think i heard somewhere that this is a general problem with the focus, something about the instruments being to close together or something.

I was just wondering if its a case of just getting a new display unit from the scrap yard and plugging out the old one and replacing it with this one or is there something else to it?