The buzzing noise could be the interference filter. It is a condenser connected across the lines in & is located where the power cable enters the machine. You will see it if you take off the lid, it is a cylindrical silver object about 2 to 3" long & maybe 1 1/2" in diameter. If you check for noises with the lid off & machine powered up it might help to pin-point the source better. Be careful! don't stick your fingers in there.
The vibration problem is probably not related to the buzzing, you need to look into that.
Mike
November 2009