Dryer and method for controlling same

A method of controlling a dryer, the dryer including a drum, a drum motor connected to the drum, a heat pump including a compressor including a compressor motor, an evaporator, a condenser, and an electronic expansion valve, a user interface, a power module configured to control power supply to the compressor motor and the drum motor, a duct accommodating the evaporator and the condenser, and configured to receive air from the drum so that the received air flows in the duct to be heated by operation of the evaporator and the condenser, and discharge the heated air to the drum, a plurality of temperature sensors configured to detect temperature of each of the heat pump, the power module, and the duct, and a storage device, the method comprising:

• controlling the storage device to store, whenever a drying operation is performed, output data from the plurality of temperature sensors and opening degree data of the electronic expansion valve;
• identifying a factor to be controlled while the drying operation is performed, from among a plurality of factors that may cause incomplete drying, by comparing at least one of the output data from the plurality of temperature sensors and the opening degree data of an electronic expansion valve with the stored data;
• and
• controlling the user interface to output a notification of the identified factor to be controlled,
• wherein the plurality of factors that may cause incomplete drying include clogging of the duct, a failure of a cooling device cooling the power module, and a refrigerant insufficiency of the heat pump.