My tv has not picture , only sound

Hi @luismartin15542

What is the model number of the TV?

What is the source of the signal to the TV e.g. TV antenna, cable box etc

If a "box" of some sort have you tried different input types/cables e.g. HDMI, AV between the box and the TV to see if video appears?

With the TV turned on (and audio being heard) try shining a flashlight at an angle close to the screen and check if you can see any images at all on the screen. They will be very faint so trying this in a darkened room may help.