Is your problem with live TV or ondemand and catchup or both, you could also check any recordings you have. If streaming services are OK and it's just live TV have you checked the coax connection to the 360 box as live TV comes down the coax cable. If it's everything have you tried a different HDMI cable and connector on the TV. You can also run the diagnostics test, you will find that in Settings, Network, Diagnostics. If everything else fails try a factory reset of the box, select the option to keep your recordings.
