My dishwasher won't start the cycle?

Hi,

My dishwasher (Hotpoint) stopped mid cycle and I managed to drain it. Since then it lights up, I can select the programme and it beeps but doesn't actually start. The beep sounds more like an error beep rather than the "yes, I'll wash your dishes" beep (it's a bit longer rather than a pip if that makes sense?). I've checked for blockages at the u-bend and just clear non-smelly water came out of the pipe. Any ideas gratefully received.