hi john,
water flow into the rinse chamber is controlled by a solenoid valve.
you will find maybe upto 3 of them under the top lid. they are easy enough to trace ie fill/rinse/final rinse.
check the two leads are firmly fixed and the valve isn't jammed but more often than not its the non repairable solenoid wiring thats failed.
go to www.espares.co.uk