I assume you have the DVD or XBox connected to the composite video or S-video ports on the EF420E. These can only be accessed with a remote control that has an Input button. The original remote had the Input button near the middle of the remote on the right side of the remote. Pressing it allowed you to toggle between TV, Video 1, and Video 2. If you do not have the original remote or the remote's Input button doesn't work, you need a replacement remote or an universal remote with an Input button. (Many of the cheapest universal remotes don't have this feature button included.) A replacement remote is available from http://remotes.com/store/esa/ef420e.html
. They have the original remote and a guaranteed to work alternative. If you choose to get another universal remote, you may need to try multiple codes until the Input button works for your TV. (Try Funai codes, if ESA isn't a listed manufacturer.)
The ESA EF420E was built by Funai. The manual is available from Funai Service: http://www.funai-corp.com/support/manuals.aspx
. The direct link to the manual is http://www.funai-corp.com/support/om/EF420E.pdf
I hope this helps.