Ok then as I said , I did not expect much out of it so I prepared your answer while waiting for your reply.
Right now you are more than likely looking at a power board problem and this model has some 7 or 8 different versions of it so if you were to look into repairing this yourself then you would first need to match yours with one of those at the link below;
You would be looking at power supply unit or power supply/ backlight inverter depending on which is in yours.
If that is not your cup of tea so to speak then to have this repaired at home could cost you around $250 parts included and perhaps $50 less if you take it to the shop yourself .
If i may be frank , considering the age of the tv and the fact that you can get a new 42" plasma tv with all the bells and whistles for around or less than $300 ,I would think twice before investing that kind of money into this one.
If you need to find repair shops near you then look at the links below and enter your zip code ;
Or this one;
This will give you a list of repair shops in your area.
You could give a call to different shops in your area to get an idea of their rates , it pays to shop around.
If that answers your question please do not forget to rate so i get paid for my time helping you and you can use the reply button before or after rating if you have other questions or need help , thank you