Sami one quick way to pinpoint the buzz is to open the freezer and hold the door switch in; if the noise changes or stops, the evaporator fan is hitting ice, which points to a defrost or blocked drain issue. After the 12–24 hour defrost, pour a cup of hot water down the freezer drain hole to clear it so the ice doesn’t come right back. If instead you hear a repeated buzz for a few seconds followed by a click and then a minute of silence, that’s the compressor trying and failing to start, and a new start relay/overload is the next cheap part to try.
