Sorry to hear about the difficulty you've been through. I'd suggest resetting the TV to factory defaults. Here are the instructions for that: http://www.samsung.com/us/support/supportOwnersHowToGuidePopup.do?howto_guide_seq=5306&prd_ia_cd=N0000043&map_seq=44729
Let me know whether that works for you. Have a good one!
So I have an LCD TV Model No. LN40A530P1F. I've had the TV for several years and never had any problems but all of a sudden I'm trying to hook up my HD cable box with an HDMI cable and it's not picking up the input. I had this TV hooked up to this same model cable box (not the same exact cable box...same type) with an HDMI just a few months ago and it worked fine. All other inputs appear to be working - it picks up the cable box when I plug it in to the A/V input but I paid for HD cable so I want HD. My xbox is also plugged into a component input and works. I've tried all 3 HDMI inputs on my TV and none work - the TV doesn't seem to recognize that anything is plugged in. I hit refresh on the source list and it says it doesn't detect any new devices. My first instinct was to assume that Comcast gave me a faulty HDMI cable based on their well established commitment to being the worst cable company on earth, but I bought a new one and it doesn't work either. I also tried plugging my xbox in with HDMI and it doesn't work either so I think it's obviously a problem with the TV and not the cable box.
I went on live chat with Samsung and they were totally useless. All the rep did was ask me to check the firmware version and then she said that it was up to date - which I find hard to believe since I don't remember EVER updating it since I've owned the TV. But in any case I doubt it's the problem since I had an HD cable box hooked up to this TV without problems just a few months ago.