I have the strangest situation that started the other night and can not figure out what my problem is. I have a 360 hooked into HDMI 1 on my TV and a satellite system hooked into HDMI 2.
Recently I lost audio on the 360 and then video right behind it. Of course the first thing I did was change which HDMI port the 360 was in. It worked. This made me believe that the HDMI port on the TV had gone out even though the TV is < 2 months old.
Just for laughs I thought I would plug the satellite into the port that the 360 had been in. Guess what, It worked, so I switched them back out and nothing.
I also changed the HDMI from my Satellite to my 360 with the port that I thought was bad and it worked.
Is it possible for a cable to only not work with 1 HDMI port but work with all others on the SAME TV?
That is strange.... I have seen this sort of thing happen with USB, I wonder if this is the same sort of thing. Try unplugging power to the TV with the HDMI cables unplugged. Plug the TV back in, turn it on, then plug in the HDMI cable for the 360 to the port it wasn't working in and see what happens.