Your TV is now in dead condition I should say. You should strart from its power supply regulation section itsef to rectify the fault. Look into the fuse, a glass fuse is there, in power supply board. If It has found blown, make sure that there is something short in either power supply regulator side, of on the other part of the printed circuit board.
You just place a fuse of same rating as used, if the fuse is blown. If the fule you installed newly also blows off, check first the retifier stalk for any leak. The stalk contains four diodes, even any one of them gets shorte, fule will blow up. If there is no leak in the retifier stalk, measure the voltage resistance across the main filter capacitor, a bulky one capacitor fitted in the power regulator section. If you see a full deflection on meter, it means that there is some dead short inside the power regualtor system.
Usually Sony uses STR regulated type power supplies, and some uses MOSFET [Metal Oxide Semiconductor Field Effect Transistors], as switching elements. Bothe of these types can be shorted, due to a high voltage spikes, or a sudden supply failure and restart.
Check out short test on these components, out of board, that is, desolder it out from the circuit board. You just resolder one by one and measure the resistance ad described above. Thus you can find out the exact component, that have a short. If any of these components shorted, check the entire power regulator section for any more component failure, like zener diode short, resistors opened, and so on. You should have a concept of soldering and a little knoledge in electronics. There will be a MOV [Metal Oxide Varistor] fitted across the power supply input, which look like a disc capacitor. it will get shorted when a certain voltage spike occures abvve its rated voltage, and apply a dead short at the supply stage. If any of them used, desolder it out and check for any leak, and is found leaky, replace it. It is used as a saftey measure, and without it the set will work fine.
Just check these and if you find any difficulty, contact me through Fixya. Ok.
on Nov 29, 2010