Delonghi Dishwasher keeps turning off/wont stay on?

My Delonghi Dishwasher DW47s/w keeps turning off. The dishwasher is turned on at the power point. The water is turned on. Okay
When I press the POWER botton on the front it wont stay on. I have to keep my finger on the POWER button and then press the START button for washer to work. If I do this it will then pump out any water in the bottom and start to work. ***BUT when you take your finger of the POWER button the washer just turns off and stops working. Do you have any idea what could be the problem please.

Shaun
November 2009