refrigerator

Backup Operating System (BOS)
The backup operating system (BOS) is an
electronically controlled duty cycle. It maintains the
refrigerator in operation if the thermistor is
disconnected or fails. The BOS maintains cooling by
controlling the heat source selected. When the
refrigerator is operating in BOS, the length of the
cooling cycle is regulated by time rather than
regulated by temperature.
To accomplish this, the BOS adjusts the length of the
cooling cycle according to the temperature setting
selected by the user; the higher the temperature
setting, the longer the cooling cycle. For example, if
the temperature setting is set to 5, raising the setting
to 6 will lengthen the cooling cycle, making the
cabinet colder

Bad thermistor or it is unplugged.....see 'other' posting for more info