OK, this looks to be a 2006 set so my advice is since you asked my bet is you are not a TV technician. And given the repair costs you want to save yourself time and money and move to outright replacements.
I see Woot pushing 47 inch LG's refurb at 399 which are pretty slim and not as heavy as your Sony.
http://www.woot.com/forums/viewpost.aspx?postid=5461365&pageindex=1&replycount=145#post5461377
Bob

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