Yes, the brushroll's operating fine. In fact this is the only thing that results in any successful cleaning.
I've managed a bit more exploratory work - I removed the cleaner head and turned the vacuum on and there was still strong suction from the cavity/hose. Then, when the cleaner head was reattached and the vacuum turned on, the suction coming out of the base of the cleaner head was very, very feeble. The suction loss seems to be 'through' the cleaner head. Any mileage in fixing of replacing the whole cleaner head?
Thanks for your help