If the seller had the �500 payment protection logo you are guaranteed to get your money back.
The seller will have to prove that the television was received - by providing a tracking number. If he cannot do that, you will get the money back very quickly.
If there was no protection logo, it may be more difficult. You will only get back any money that he has in his paypal account. If he has nothing, you wil get nothing. You will then have to pursue it through the small claims court.