try plugging it into the scart socket which ure video is plugged into. if it works in there, then u know its the 2nd scart socket. If its the same, thne u know it either the scart lead,scart socket or the dvd player.
U Said uve already tried different scart leads so it cant be that.when u r playing a dvd, wiggle the scart lead near the socket on both the dvd player and tv. if that doesnt do anything then u know its not ure sockets.
This means its the dvd player. all dvd plyers have their own volume control. make sure this is fully up(not the tv, the dvd player itself). if they all fail, make sure the tv is tuned in properly and if all these fail, thne use the normal red/yellow cables which u should have connections on the back.front of ure tv and back of ure dvd player. If thats works, then u know u have a dodgy dvd/tv scart socket