I have a Sony dav-tz140 dvd player thathas started selecting which discs it will play ,some it has played ok then it decides it will not play them just says no disc and others it plays but it sticks and jumps ,just tried with a brand new dvd and it sticks and jumps but will play others fine tried putting a cleaner in it but made no difference has anyone come across this before and is there a cure or is it a new player.