A friend has asked my opinion on this, and I have no idea. Is there a
general reliability problem with DVD transports?

Her Philips machine can play a (rented movie) DVD for between 15 and 45
minutes, after which time a NO DISC or DISC ERROR is displayed. Reinserting
the DVD doesn't help, although it will sometimes play for 1 - 2 minutes.
Playing a different DVD makes no difference.

The machine is about 18 months old; so she's not very happy. She is also
wondering how reliable these players are, as a lot of her friends are having
reliability problems with their DVD players.

Any ideas what the problem might be?

Stephen