Televisions today come with a wide variety of inputs to accommodate many of the modern technologies available, such as video game consoles, surround sound systems and DVD and Blu-ray players. However, each external system requires a different video mode on the TV so it knows what to display. This is typically done with the remote, but if your remote's missing in action or broken, you can also change the video mode quite easily by using the buttons on the television itself.
Check the bottom or side of the TV for buttons labelled "Video" or "Input." Pressing this button or buttons will start the TV cycling through its various video channels. Stop pressing buttons when you've reached the desired channel. Occasionally a TV will have all of its video channels assigned to a single button.
Press the "Menu" button on the TV and use the volume and channel buttons to cycle through the menu until you reach the video settings, where you can set the TV to the desired video channel. See your TV's instruction manual for directions specific to your model for navigating through the menu.
Do nothing! Many modern TVs automatically detect when audio or video signals are travelling to your TV and will adjust to the proper channel by themselves. Simply turn on your DVD player or game console and the TV will automatically flip to the right channel.
If you have remote issues, simply place a piece of Velcro on the bottom of the remote and another to the side of your TV; this will provide a safe place for you to always put your remote. You can even order a spare remote directly from the TV's manufacturer.