Zanussi DE6744S D/W PCB ?

PNC 911888019 S/No 14540389

I fitted an IWMS system to this machine around 12 months ago.

Called this morning, complaint of no drain & sticking on cycle.

Switched on and heard a buzzing noise. Thinks, blocked or faulty pump or capacitor.

Circ/drain motor appears perfect, capacitor OK. The buzzing seems to be coming from one or both of the two solenoid valves mounted on the IWMS matrix at the bottom near the inlet valve.

Drained manually and set back to wash, once again when I would expect the drain pump to kick in these valves are buzzing. After a short while the programme advances and the machine then fills perfectly and proceeds to wash.
However it will not drain, only energise these valves if I attempt to reset.

I’m thinking faulty PCB, any other possible causes?

Jim.