My sanyo tv light up only one side

cynthkor this could be a power board issue, as well as a T-con board issue, and of course a bad panel (driver boards). We would need to know what model your Sanyo TV is. Then it will really help if you post an image of what your screen is displaying. Use this guide Adding images to an existing question to post images with your question. That will allow us to see what you see. Unplug your TV remove the back cover and take a look at the flat ribbon cables. Make sure those are all properly connected. Pay particular attention to the board that has two cables going to the panel. That is your T-con board and hopefully the culprit. Ultimately be prepared to have some basic tools and a multimeter to check things out.