An audio/video output device comprising: a first output component configured to execute video and audio output; a second output component configured to execute video and audio output and intended for use as a dedicated audio output port; an audio memory configured to store audio signal; a video memory configured to store video signal; and a controller configured to: determine, in response to a connection of an external device to the second output component, whether the external device supports video input, when it is determined that the external device does not support video input, output the audio signal stored in the audio memory from the second output component, and allocate the entire memory area of the video memory to the first output component, when it is determined that the external device supports video input, temporarily allocate part of an area of the video memory that has been allocated to the first output component to the second output component, and output an OSD video signal from the second output component using the allocated part of the area to display on the external device a notification screen indicating that the connection is wrong and that the second output component is dedicated to audio output. a first output component configured to execute video and audio output; a second output component configured to execute video and audio output and intended for use as a dedicated audio output port; an audio memory configured to store audio signal; a video memory configured to store video signal; and a controller configured to: determine, in response to a connection of an external device to the second output component, whether the external device supports video input, when it is determined that the external device does not support video input, output the audio signal stored in the audio memory from the second output component, and allocate the entire memory area of the video memory to the first output component, when it is determined that the external device supports video input, temporarily allocate part of an area of the video memory that has been allocated to the first output component to the second output component, and output an OSD video signal from the second output component using the allocated part of the area to display on the external device a notification screen indicating that the connection is wrong and that the second output component is dedicated to audio output. determine, in response to a connection of an external device to the second output component, whether the external device supports video input, when it is determined that the external device does not support video input, output the audio signal stored in the audio memory from the second output component, and allocate the entire memory area of the video memory to the first output component, output the audio signal stored in the audio memory from the second output component, and allocate the entire memory area of the video memory to the first output component, when it is determined that the external device supports video input, temporarily allocate part of an area of the video memory that has been allocated to the first output component to the second output component, and output an OSD video signal from the second output component using the allocated part of the area to display on the external device a notification screen indicating that the connection is wrong and that the second output component is dedicated to audio output. temporarily allocate part of an area of the video memory that has been allocated to the first output component to the second output component, and output an OSD video signal from the second output component using the allocated part of the area to display on the external device a notification screen indicating that the connection is wrong and that the second output component is dedicated to audio output.