Ariston LSI61 Dishwasher

Customer says the programme button was dodgy for some time and had to be pressed lots of times before anything happened but now it does not work at all. I’ve checked continuity on the button itself and it is making circuit when pressed. Will it be a PCB fault or could the electronics be detecting a fault elsewhere and disabling the programme selection? I generally only do more elderly dishwashers as I find the modern ones too difficult to get at the innards but I was there fixing the tumble dryer and was then asked to do the dishwasher.