Try another HDMI cable, and a factory reset on Youview box next.
try your TV's inbuilt tuner to make sure it's not a TV fault, last time that happened to me my TV was kaput and had to be replaced.
Try another HDMI cable, and a factory reset on Youview box next.
try your TV's inbuilt tuner to make sure it's not a TV fault, last time that happened to me my TV was kaput and had to be replaced.