The TV/Video button on the original remote for the KDL-26S2000 should let you cycle through the inputs on the TV. This button is at the upper left of the remote. (However, if you have set the system to Skip inputs, you may need to remove the skip option.)

There is also a TV/Video button on the front of the TV. It's the second button from the left on the panel (it's just to the right of the menu button).

To reset the input list, press Menu and navigate to Settings. Select the Setup sub-menu and then select the Label Video Inputs. Give the input any label other than skip.

Some TVs work best if the TV is turned on and set to that input source before you turn on the source device.

For additional information and pictures of the menus, see the manual. It is available from Sony support: http://esupport.sony.com/US/perl/model-home.pl?mdl=KDL26S2000&template_id=1&region_id=1&tab=manuals#/manualsTab (see the Manuals, Specs and Warranty tab). The direct link to the manual is http://www.docs.sony.com/release/KDL40S2000.pdf .
I hope this helps.

Cindy Wells