Pretty well all modern tv's use electronic adjustments for the picture settings - scan, focus, pincushion, convergence etc., unlike the "old" days when you slid the scan coils along the neck of the tube! To access these menus usually requires a specific sequence of key presses on the remote, a combination that, under normal use, would never occur.
The fact that you have to ask indicates that you're perhaps unfamiliar with tv adjustments. My advice in that case is DON'T EVEN THINK ABOUT IT!
Even if you should manage to get the access codes, unless you know what you're doing you can quite easily make your tv into a non-tv :eek:
(Just a little friendly advice )