Satisfactory outcome.
Took the unit out of the boot in anticipation of sending away for service, decided to bite the bullet and have a looksee, thinkng message NO DISC
may mean mechanical problem rather than faulty laser.
After cleaning lubricating moving parts with WD 40 on pencil brush tried unit again with successfull outcome, still working after numerous disc changes. Hope my luck holds as during last two weeks whilst on holiday my electric toothbrush packed up, my mobile phone lost all its functions and on my return I blew the steam iron. l o l .
I have this way with electrical gadgets.
geo912.