Welcome to the forum and irv2.
If you go to QT's # 3
there are many conversions of TV's to LCD's.
The screws you removed maybe into a metal plate on the bottom of TV you may also have screws in the two side cabinets screwed into boards that are attached to the dress frame around the TV.
When you remove them the whole face frame will slide out of box enclosure.
There are more TV conversions in QT's 1 & 2.