Toshiba TV (Fenay Bridge HD8)

This is a Toshiba Smart TV, model is as shown in the picture. It’s been fine for a few years but recently it’s been running for about half an hour from switching on, then the picture goes off, although the sound is still audible. I guess it’s about 24” but this can be checked against the model. I don’t know if it’s a simple repair but if you think it’s for you, let me know