Beko DW451 making thumping noise during fill cycle

Morning, firstly I hope everybody is safe and well.

My Beko DW451 has just started making a thumping noise during what appears to be the fill cycle.

I have tried the usual check the filters, sump, drain pipe etc and they all seem fine.

I have run the test cycle and it reports no errors.

Done the usual google searches and this is the closest I can find to the same prob, although yet to determine if the water gets hot, testing that now.
https://www.ukwhitegoods.co.uk/forums/forum/public-support-forums/help-and-support/dishwasher-help-forum/86181-beko-dwd4310s-thumping-noise-on-fill-cycle

The post above looks a good bet but its not clear on what the PCB is (other than Printer Circuit Board), where it is and how to replace it – I wonder if anybody is able to help ?

Thanks
Gav