Since early 2003, an item has got to last a 'reasonable' period after purchase, subject to no misuse. 1/2 years before a TV is borked would probably be considered as the item not being fit for intended use. If your TV is <3 years old it may be worth going back to the retailer for a chat.
However, as with most laws, the Consumer Act is not plain sailing and tries to be fair to consumer AND retailer. You have to prove that the item did not last as long as it should have done...... and here lies the problem. How long should a TV last? 1. 2. 3. 4, 5 years? There are no set rules and the onus is on the complainant to prove fault. A new 32" TV costs around £300 and you have to balance this with the hassle of County Court etc.
If the TV is totally borked then your home insurance should cover you. If a TV does not work and it is not the tube, a repair should cost no more than £60 from a local engineer....all they do is whip out a circuit board and replace it with another. It may be worth getting a quote and phoning your insurance company.