Whirlpool ADG 993 fills but won't wash

Question

Hi, Our dishwasher fills with water but then stops. We can drain it but thats all. The green light under the start button has flashed continuosly. I have powered off at the main switch and back on again, on one occasion this seemed to work, the washer blades rotated but after a very short amount of time it stopped again and that was that. Any advice would be much appreciated. Martin