This will probably be too late to do much good now, but in case anyone else comes across the same problem. My TCL 55P605 TV started having this same problem last week. After doing some research, I took a gamble and purchased a new T-Con board for $25. It only took about 10 minutes to install (remove the back panel, unhook three cables and 4 screws, then reverse) and so far, the TV has been back to working like normal.