How can I fix my Bush IDLCD27TV006-No Signal problem?

Bush IDLCD27TV006. Not finding any channels on auto scan.
Originally I could watch many channels but had no signal on, around, seven channels. I tested TV on a known serviceable aerial connector but still same peoblem. I then decided totry resetting TV. Now I have no channels at all and when I try auto scan it can't find any channels.
Any ideas please?