Even USCIS released the name check memo (這裏, we still see lots of people stuck with name check, and turned out that most of them are not due to real security check, but for some technical reason, for example, mistake with A#, lost feedback record from FBI, lost files, etc ). So you first need to go to infopass (make a copy of the receipt and save for future) to find out what's real reason. For some case, only WOM lawsuit can solve the problem. See many people solve their problem via WOM 這裏
So in general, if you live in friendly district court, case pending over 1.5-2yrs, you have done something to push your case, then WOM will quickly solve the mistery.