An electronic device includes a number of hard disk devices, a detection system, and a power supply. The detection system includes a detection device, a controller, and an emergency power supply. The power supply is coupled to the hard disk devices and the detection system, to power the hard disk devices and the detection system. The emergency power supply is coupled to the controller and the display device, to power the controller and the display device. The controller is coupled to the detection device and the display device. The detection device detects data of the hard disk devices and transmits the data to the controller. The controller receives the data from the detection device, and transmits the data to the display device. The display device displays the data.