Zanussi semi intergrated dishwasher drain problem

Got a Zanussi S/I dishwasher that wont drain. Its the type that uses the same motor for circulation and reverses for drain. Machine wash pump working fine but does not seem to drain. Can i then rule out the capacitor being faulty? Yes i thought.
Spoke to the local Serviceforce boys who said check for stripped impellor. Fine i told them. ‘Then it must be the pump’ they said. Fit new pump and machine gives about 3x 5 second spurts during the drying cycle but nothing on any other cycles. ‘Ah, that will be the timer then’ they said. Customer is a retired electrical engineer so would like to get it right this time. Can you experts out there help?