I had the same problem, this humming vibrating noise when powered on.
I took the camera apart and opened the lens system and saw that there was lots of dust particles where the autofocus is. The autofocus is no motor but a sliding head on a magnet carrying a focus lens.
I cleaned this place, the focus lens and the image sensor using a small painting brush and an air blower, put it all together and the noise was gone! What more, the pictures became a lot clearer and well focused.