Buzzing sound there is a buzzing sound that wont stop unless you open the fridge.

If noise stops when you open the door, you may have a noisy fan (or could have ice build up, causing fan blade to hit ice and cause noise). I gather it is a frost-free model ie has a fan in the freezer compartment. If noise is caused by fan hitting ice build up, you may have a problem with the auto defrost system, as you should not get ice build up in a frost free.
Noise stops when you open door because fan turns off when door is opened.

There is a little box behind of the ice bucket at the freezer. Sound comes from there. If you hit couple times, sounds will go away.