Product review (1 stars): Poor quality control
I sounds like you either get a good one or a bad one. I got a bad one. The transformer constantly buzzes. One of the bulb sockets is defective and requires constant fiddling with the bulb - which eventually ruins it. At least the fan still works. I recently remodeled and this unit has been driving me crazy for the last year in my otherwise awesome new kitchen. I'm going to replace it with anything but a Braun product.