Firenzi SF904WH error F03

I have a Firenzi SF904WH electric oven. It has long had a problem where sometimes the oven temperature will reset to 160 (and any timer will be cancelled). This weekend I had to switch the main house power off briefly, when I switched it back on and tried to use the oven it had a bit of a “fit” – oven temp went to 160, flashing, then after a few seconds it shut down and displayed F03. Tried switching off from the wall and back on again, now just displays F03 and nothing works.

I read somewhere that this might be a PCB fault, problem is this site lists 2 different ones – there’s one which sits immediately behind the control knobs, in fact the spindles for the knobs appear to be integral to the PCB – this I could access and replace quite easily (I found that cleaning the connectors on this board helped in the past with the “reset to 160” problem). But I don’t know where the other (bigger) PCB sits and whether it is easily accessible to replace.

Looking on other sites has only added to my confusion – eSpares.co.uk lists only one PCB part for this oven – the one with the 2 control spindles – but with a different part number and quite different price to the one on UKWhitegoods!

So – to cut to the chase – which board do I need to replace to fix this problem – or do I need to get both – and how easy is this to do (do I have to disassemble the entire thing to get to it)?

Thanks in advance for any advice!