That sounds out of the ordinary, and I'm sorry to hear that you're having this issue. I would recommend setting up a service ticket online, and you can do that here:
Just out of curiosity, what devices do you have connected to the television?
This is my second set with the same problem. I exchanged the first one thinking it was a fluke. But I guess not. HDMI port 2 is the only port that works. The other 3 just replicate what is on port 2. The first time it happened after a month and the second time it happened after 2 months. Has anyone experienced this problem?