@zou "i tried all the plugging and unplugging things i seen online, nothing worked." not sure what all that entails. Unplug the TV, unplug everything that plugd into the TV (cable box/game console/everything. Then hold down the power button for about a minute or so. Now plug one video source back in, preferably not the cable box. Last plug your TV back in. Now try and turn it on.
If it continues to flash once you plug it in, you do need to check the power supply. Remove the back cover (unplug your TV of course) and take a look at the power board. Post some good pictures of your boards with your question so we can try and assist you. Adding images to an existing question