If, like me, you bought a Mac from John Lewis because it came with a two year warranty, then beware. If you phone up to get it fixed when it’s gone wrong, you’re quite likely to end up speaking to someone who gives you duff information - for example, trying to pass you off to Apple. This two year warranty is the responsibility of JL and not anyone else. Persevere and you should be able to get it fixed under the terms of the agreement for nothing. Like they promised.