Nikon D3300 Reference Manual page 236

3
Tune the television to the video channel.
4
Turn the camera on and press the K button.
During playback, images will be displayed on the television
screen. Note that the edges of images may not be displayed.
A
Video Mode
If no image is displayed, check that camera is correctly connected and
that the option selected for Video mode (0 260) matches the video
standard used in the TV.
A
Television Playback
Use of an AC adapter (available separately) is recommended for
extended playback.
216 Connections