This is a Sony KV24WX1U (BE3D chassis?) tv, which goes off and displays two flashs of the red standby led, when the teletext button on the remote is pressed. For a split second the screen shows text but it looks dropped with a black band across the top. Also, I see the tv goes off the same way when the format button is pressed. Please, to suggest what area of the circuit to check as I am not familiar with this up to date stuff. I have access to the be3d chassis diagram. Thanks to you.
David