Later this week I'm going to try the stuck pixel fix and heating the panel at the same time to see if that fixes it.
I know it's not going to be a great loss if you trash this thing completely ... but I get nervous when people talk about applying heat to an LCD panel.
Also, thanks for the invitation, but being in Sydney makes a visit a tad pricey.
Revisiting the problem, it seems curious that the damage is primarily noticeable in one of the primary colours - but aside from that, the shape is, to my mind, very consistent with water intrusion.
I did have a thought though - as to whether there might be an effect of water on the polarisation orientation. LCD displays have two polarising layers. One is the LCD sheet itself, where the polarisation is controlled by electrical signals. The other is a fixed polarising filter. If water were to get
in between these, then I wonder what effect would be seen?
I have a couple of old LCD screens with failed backlights that I might like to have a play with - but time is my enemy at the moment - and I would have to clear off a large area to open up the one I would prefer to use.
As far as opening up LCD TVs is concerned, my experience is very limited. I haven't opened up units as old as yours and from a couple of Youtube videos I've seen, they could involve a fair bit of mechanical disassembly, which might be involved. The oldest unit I've opened up is a 5 year old Samsung TV - and it consisted of wrangling a few screws and a lot of plastic clips which weren't too hard to manage (with a bit of care, of course). If you want to try this, set yourself a flat area, twice the size of the TV, with something soft to protect the screen. Most of the disassembly requires normal care - but when you get to the edge of the LCD panel itself, you will encounter a mass of edge connectors. Treat these with extreme care. My only purpose for going to this extent would be to separate the polarising sheet from the LCD sheet and use a lint free cloth to
very carefully clean the two facing surfaces - then reassembling and see what happens.
But, to be honest, I would put this down as a last-ditch effort.