My son's 32" Samsung smart TV, which is only about 3yrs old developed a fault a few months ago. You could see the backlights come on, but nothing was displayed on screen. Our TV shop offers a free quote service for repairs and diagnosed a faulty T-Con board. They wanted £110 to repair it. We couldn't decide if it was worth repairing as a replacement would cost about £250. It has been sat on the floor looking lonely for a few months now.
Inspired by Dave I took the back off the TV and removed the board. The whole procedure was very simple, the main difficulty was trying to stop the dog grabbing the screws off the table. I Googled for a replacement board and it seemed that it was either out of stock or a used one was about £60 on eBay. I have managed to find a supplier of the original board in China and should receive a brand new board for £33 in a few weeks.,
I think the quote for repair was reasonable, given that the board would have cost them about £60 plus an hours labour.