I have a DAV 300 system that after 2 years has decided that it does not wish to read dvd's any more. After inserting a disk it spins around then states "no disk" I can eject and reload a few times and then it will play!!! What is up with my machine - is it dead or is it just a case of buying a lens cleaning disk? I am loathe to buy a disk if it is beyond repair Please help!!