As stated above, one should never go into the SM unless you are absolutely sure of what you are doing, regardless of what posts or setting changes someone says you can do. It is just not worth it. As you have seen, that is the quickest way to brick a tv. Screwing up the SM settings voids your warranty. As suggested, you can try to take it back to the store and say you're not satisfied with the pq and hope that they don't examine the set before authorizing your return. I would imagine that you could call Samsung and ask for a service call, even if you're not under warranty, but it is up to them as to whether they want to spend the time and resources to fix your set. Some SM setting are done at the factory and may not be able to be corrected in the field. Good luck.