I will give you your answer and hope you will do the right thing and rate me positively on you read it .
This is a typical case of weak/vented capacitors on the power supply circuit and although there are capacitor kits that sell to repair this you will need to be handy with a solder iron and , if you are into repairing this yourself then I would suggest to simply replace that board part # BN44-00167C that you can get at the link below for $45 ;
This is Plug&Play ,no solder or adjustments and if you or a friend is handy with a screwdriver and can remove the back cover then you can do this yourself, no special tools required.
If that is not your cup of tea so to speak then to have this repaired at home could cost you around $200 parts included and perhaps $50 less if you take it to the shop yourself .
If you need to find repair shops near you then look at the link below and enter your zip code ;
This will give you a list of NESDA member repair shops in your area.
This list may be limited though and you may find more the yellow pages or simply google "tv repairs" and the name of your town .
You could give a call to different shops in your area to get an idea of their rates , it pays to shop around but if i may be frank , considering the age of the tv and the fact that you can get a new 40" tv with all the bells and whistles for around or less than $250 ,I would think twice before investing that kind of money into this one.
I think your money would be better invested in a new tv .
Let me know if you have other questions and if not then please do not forget to rate by clicking on the star icons at the top, then click on Submit so i get paid for my time helping you .
Also note that it will not close this post , you can come back here at any time if you need further info or help .