The tuner is an 'always on' connection, which means that it's the default when exiting streaming services, thumbdrive content and powering on. In some cases, I've seen it reported that you can turn the TV off first and then the cable box, and then re-start the cable box and then the TV for it to work, but that has varied based on what several people here have posted.
There is not a way to set a default input with a HDMI or other input.
I have a DirecTV HD DVR that I just connected to my LN52B750 via HDMI input 1, as well as a Blu-ray player in HDMI input 2. I do not use cable. When I turn on/off the TV, the TV automatically defaults to the cable input which means a screen full of snow. Then I have to click more buttons to switch over to HDMI, which is very frustrating..
How can I prevent the TV from using the cable input as a valid source? Can I disable the coax or set HDMI input 1 as the default or is there another solution to accomplish this like sorting the order of input connections? Will new firmware correct this problem? Thanks for any help?