no pictures but sounds is okay

@gabazeen you are not providing us with enough information. We do need to at least know what model your TV is. You want to start by checking if the red power LED on the front of the TV and see if it is flashing. If it does, we need to know how many times before it pauses and flashes all over again.

First thing you want to try is to reset your TV. Unplug the TV for a few minutes, then plug it back in. Sometimes this clears any issue. Since you have audio , you know that at least part of your main board still works. Now, in a darkened room turn the TV to a station where you have audio. Shine a flashlight at an angle against the screen. See if you can make things out like silhouettes, menus etc. If so, then you know it is your backlight (bad power board, bad backlight array). If you do not see anything then there is a list of possible failures includes the power supply, the main board, the scan drive or sustain boards, T-Con board and of course the panel itself. You'll have to remove the back cover and take a look at the boards. checking for any obviously damaged looking components. You can always post some GOOD pictures of your boards with your QUESTION so that we can see what you see. Once we know what models your TV is and if it generates an error code we can probably narrow this down.

Adding images to an existing question - iFixit Repair Guide