Sony KDL-46XBR6 partial dark screen

NTD

This TV's LCD screen has a dark vertical band in the centre, increasing gradually to normal brightness on either side (please see photo). The band in the centre still shows the video; it's just not backlit.

I'm guessing the backlighting is the problem, and that the backlight components are an integral part of the screen (i.e., not individually replaceable), meaning the TV is toast.

Am I right about this? It's only later Sony TVs that came with LED backlighting that's replaceable independently of the screen, correct?

Thanks in advance for any help I can get!