Probably dirty laser lens by the sound of the symptoms.

Take a cotton wool bud and try gently cleaning the lens with a circular motion. Don't press too hard!

Ideally the bud would be damped in isopropanol but as you are unlikely to have any a dry one will have to do.

Try the CD again. Let us know what happens

Thanks Graham.  I'm off to buy isopropanol. 

 jo

Graham - the lens cleaning did not work.  I do notice that when the CD cover closes over the cds the cover appears to be pushing down on the cd unit.  Is this common or is there perhaps an alignment issue?

Jo

Yes there will appear to be pressure on the CD mechanism from the door. This is quite normal.

There are several possible reasons for your problem.

Dirty or incompatible cd's, bad capacitors on the cd servo board, faulty laser are but three possibilities. Assuming that you have played these cd's before with no problems then we are now coming down to solutions which require the attention of a service tech or similar type of person.

Where are you situated?