Re: Lamona dishwasher LAM8602
Have you checked the anti flood system? Maybe a stuck microswitch or jammed float?
Inlet valves can test OK but still not allow water to pass. Check power is going to the inlet valve after initial drain sequence. depending on the model it may take a minute. Also check the pressure switch hose for blockages or the operation of the pressure switch. 30 seconds cut off is usually a time out of the pre wash drain. It may still think there is water in the appliance but its actually a pressure switch fault.
If no luck with any of them and no error codes flashing then I think your diagnoses is correct.