TimEtherington

@Dylan Woods Unfortunately not. I’ve been unable to establish the component values or find the circuit diagram. My options seem to be the same as yours - replace the fan or the whole unit. For financial reasons I am probably going with the former.

@Dylan Woods I share your pain. I’ve had two units fail, with the same symptoms, each after 5 years. I stripped down the last one and found moisture damage within the fan motor, affecting a circuit board which tells the main circuit the speed the fan is running. @Sgot Yaflowrates - do you still have any of your replacement stock available?