Problem with Sanyo ST-21KX2 it shuts off...

Question

Hi,I have a problem with my Sanyo TV. What happens is that it automatically shuts off after around an hour or more of use. I believe that if it is already hot it will automatically turn off on its on and when you turn it back on after 5 minutes or so it will turn off again.I tried to open the back cover of the TV, then tried to focus an electric fan at the circuit. It doesn't turn off.I tried to bring it to a repair center and they told me that the problem is the power supply but they are charging me a lot to fix this.Is there a way that I can fix it on my own?