Re: Belling format 600X (old one) oven fan
Was it a genuine fan motor?…fitted a pattern one now and again which have a built in TOC which plays up….just a thought because you are correct, the fan motor should run all the time the oven is on.
The pcb’s work slightly differently depending on the age, most are like a relay board using triacs (maybe it should be calles a triac board? 😆 ) switching the cooling fan, interior lights etc. The later ones IIRC gave an overrun on the cooling fan.