Try this :
Using the Sony remote > turn off the TV
Then using the Sony remote , press :
Display > 5 > Volume Down > Power
This will bring up the Self Test Menu < DO NOT PRESS ANY BUTTONS >
They should be all "0..." , if not , write down the error number of the item that has failed.
If you see all Zero`s , thats great , if not you will be able to take that info to Sony or a Sony tech and they should be able to give you a repair quote.
Now , if you do see all ZERO`S , try this :
Turn the TV off by remote , then PRESS and HOLD the remote power button ( while aiming the remote at the sensor ) and turn the TV on by using the power button on the TV.
The TV will start then stop then start and reset itself and you will have ALL FACTORY SETTINGS.
If you have done any calibration write down the values before reset.
Best of luck , I have the same set in a 40" version and it`s a great TV , well worth fixing even though it`s only 60Hz refresh rate.
Take care and good luck