Kitchen Aid dishwasher won't start

Question

Two days ago, it was running fine. Then I tried to start it the same way I always do...select the cycle and press "start"....but this time when I pressed the "start" button...nothing happens. The green lights come on, but it just sits there and won't start or run. We tried disconnecting it from the power source for 5 hours, but when we reconnected it...still the same. Any ideas?