Hi Guys,
I have the same trouble what we need to do is change the powers supply, Mine is completely dead now and went with a bang it flickered did all that crap that every one else's display is doing from the very first day I got 3 years ago.
I really don't think there is any thing apple about this display of mine any more, I have change almost all of the parts in this display and all I need now is the Australian conversion power supply.
I need to find out where I can get one and how to replace it, cost of the part, oh yeah I live in Australia so I really need Australian power supply for the LCD thunderbolt display.
I did not know they made a LED display there is no led lighting in the thunder bolt I have pulled mine apart many times to fix problem after problem and apple want to make you pay $100's of dollars to fix it.