Just to complete this story, I fitted the new power module today and the desk was restored to life. Fairly simple fix apart from the million screws holding it together. Why it failed is another story, could be just age (3 yrs is not too impressive though) or maybe a power problem, though nothing else has been affected. While it's been down we borrowed a newer X32 from a local school and it was interesting to see the changes made in the design. Screw heads all over the front panel and rubbery buttons were the most obvious changes, could not tell if the faders had also been updated.