DIAGNOSIS The unit likely shifted during shipping. Internal components, specifically the fan or compressor mount, are vibrating against the housing.
FIX Power off and unplug the unit. Remove the ice basket and internal tray. Gently tilt the machine and listen for movement. Apply firm pressure to the top and side panels to reseat them. A distinct click indicates a panel snapping back into place. Plug it in and listen. The noise should be a consistent, low hum.
IF THAT DIDN'T WORK The drain pump or fan blade itself may be contacting the housing. Visually inspect the fan area through the rear vent for obstruction. A piece of packing foam is a common culprit.
HEADS UP Do not operate the machine with a persistent metallic grinding noise. This indicates a compressor issue and requires contacting support immediately.