Sound with no picture

@twiggy1967 turn your TV on in a darkened room and place it on a station where you know you would have a signal. Shine a flashlight at an angle against the screen. See if you can make out any movement etc. ion the screen. If so you know you have an issue with the backlight. Unplug the set and remove the back of your TV then take a look at all the boards. Check for any obvious damage like domed, leaking capacitors, loose wires etc. After that check the fuses on the power supply as well as the T-con board. Post some images of your boards with your question so we can see what you see. Use this guide iFixitでの質問に画像を追加する方法 for that so we can see what you see and hopefully guide you some more.