It's entirely possible that the TCON is causing this, the problem is that there's no guarantee. The problem can also be the panel (the entire screen), and that, of course, would be bad news.
Also, a TCON board is about $76, so even if a tech were replacing it, it's hardly the cost of a new TV.
But if you want to try it, you have nothing to lose (except $76!).
The part number for the board is 1-857-128-12, and if you click on Encompass and log in as a guest, you can order it from them. Note that you will initially have to pay $166.15 for the part, but when they get the old one back, you get a $90 refund.
Best of luck to you, let me know how it goews or if you have other questions, and thanks for using JustAnswer!