Screen not working at all , the System Light turns on/off only

Hi Every one ,

so here is what happened , My LG IPS TV was working fine , then suddenly the screen went black and only the voice was working.

I turned it off to and on again , and then every thing stopped working. only the TV on/off light is working now when I turn the TV on/off from the remote.

I unplugged all HDMI cables , and tried , nothing is working … the TV screen is not working and the voice is not working … it is dead.

I want to repair it myself , what should I check for ?