Hello. hi...i want to find out something.My tv was producing sound and not picture, so i took it

Question

hi...i want to find out something.My tv was producing sound and not picture, so i took it the tv repair shop, and they said it is the power supply. I want to know if this can be possible or these guys are trying to grab my money for nothing?Pliz help, yu helped my cousin and hope u can help me tooabes