If there are NO lights flashing at the top of the unit, but the unit is beeping as though you left the door open, try removing the panel at the top of the fridge unit on the inside of the door. This is where the door sensor magnets are located. Either one or both of the magnets have become unseated, therefore cannot detect that the door is closed. Just reseat the magnet into it's housing, pop the panel back on, and bob's yer Auntie's live in loverr!

Blue Doodles, February 2010