A fine green vertical line displayed on the Sony Bravia 46.

Thats a pixel data problem, there's no data being sent to that row of pixels so they don't change color. This is a pixel address registry (PAR) issue and the PAR circuits need to be serviced its usually due to open or shorted SMT components on the PAR circuits. PAR also sends data, voltage, and control to each pixel, the green line you see are pixels that have voltage but because there's no data sent too them their all green because there's no control. If the pixels have voltage but no data or control they show up as green red, blue, yellow, or whit line vertically down the LCD panel. The vertical-horizontal section of PAR are controlled by 16 to 32 bit micro-controllers which may need replacing. If its under warranty take it back if not have your local repair center fix the tv for you...

cheek to see if you vidoe cable is pluged in right

did anyone fiddel with the light settings on you tv?