There are lots of content about TCON operation. Blank screen could be but in large screens there are 2 or more TCONs so to get a total blank it's usually some other board, connection or power issue.
You can't diagnose and be sure without spares and the service manual. You can ask and see what folk think but again you are not sure till you swap and it works again. No tech I know will tell you "It's this" without the set being on the bench and checked out, swaps done and fixed. Well the new techs will but that shine wears off fast.
I have an LG 55lf6100-UA,it has backlights and sound but no video image,where is my problem area,tcon or main board....thanks for any help!!