I had a funny un' turned out to be a zener on the T'con, have you tried powering with Tcon disconnected.... this was a Wharfdale LT26K1CB, a zener was leaky it's marking is 'CCD KE' a 5Volt type from what I gather, luckily I found one on a Samsung Tcon, but before fitting it I used a ..... standard wire ended 5.1V zener, this brought the set back to life.
In my case I changed and reprogrammed the Eprom - I now had a set I could switch off and on and it'd trip off just before the backlight came fully up, just about saw feint flicker gave the show away - something it'd never do before - the Tcon was the only board I never checked, why I made a bee line for that 5V zener I don't know.
Samsung can suffer from this problem, always worth checking it's Tcon or it's ribbon cable by disconnection just to see if there is any variation is the symptoms. Thought I'd just give it a mention.
Dave.
