Diplomat ADP8500 Suspected faulty pcb

Hi All,
I inherited this dishwasher when I bought my house a few years ago, No real problems with it, other than having to replace the heat exchanger a couple of years ago.
Recently the dishwasher would pulse at the start of the cycle for several minutes, but would then continue to run through the cycle and get the dishes nice and clean. But last week it just died and would just pulse and hum. After searching this site, all signs pointed to the infamous circulation pump. I bought one and replaced it, thinking this would fix the problem with no joy.
Machine is still filling and draining. I monitored the supply at the drain pump and found that the supply voltage was continuosly going on and off, causing the pulsing pump/ drain noise.
I’m now pretty certain that the problem is the pcb, I have inspected it for dry joints and burnt out tracks and cant see any, also cant find any circuit diagrams to diagnose the board myself.

Has anyone seen similar problems like this?? Also Im unsure whether to gamble on a new pcb which I can buy for £50 or accept that 6 years is about right for the life of a dishwasher and buy a new dishwasher, which then leads to how easy is it to replace these dishwashers as we have the matching facia panel the same colour as our kitchen cabinets??