A video device includes at least one of an input connector and an output connector connectible with a video-signal cable, wherein the input connector is connected to a first resistor coupled with a predetermined potential and oppositely connected to a first signal line of the video-signal cable connected to a second resistor of a second video device, and wherein the output connector is connected to a third resistor coupled with a ground potential and oppositely connected to a second signal line of the video-signal cable connected to a fourth resistor of a third video device; and a connection determination part configured to determine a normal connection of the video-signal cable connected to the input connector based on a potential of the first signal line or to determine a normal connection of the video-signal cable connected to the output connector based on a potential of the second signal line.