If you are not getting captions on your HD channels at all, you may need to inspect your cable/satellite receiver box or your cabling system:
- If you use satellite or cable TV, the most common HD cable connecting your network box to the TV is called an HDMI cable. The HDMI cable cannot transfer closed caption data. Usually this is not a problem because you're managing the TV through a cable or satellite box, which should decode the captions before it goes through the cable to the TV.
So check to make sure that the cable or satellite box enables closed captions. Sometimes you may have to turn off ("suspend") the cable/satellite box in order to access its caption control menu.
If you cannot turn on captions on the cable/satellite box then call your service provider and ask them to replace the box with one that will enable closed captions.
- Most DVD players do not pass through captions, so if you run the cabling through your DVD player, it may be stripping the HD captions. Consider re-setting the cables so they do not run through the DVD player. (The best solution is a separate a/v receiver that manages how all external boxes interface with the TV.) If you must run the cables through the DVD player, or if you are trying to play an HD DVD, use standard component cables (red and white jacks) or an "S" cable rather than the HDMI cable.
If you want to learn more, the CEA (Consumer Electronics Association has written a nice, in-depth article about why captioning works differently in hi-def and other digital television setups.