What is wrong with my hedge trimmer?

I have a landxcape 600w GHT610N Hedge Trimmer which has just suddenly stopped working. I was using it for longer than recommended but it was working when I finished but next day was completely dead. Any ideas? Having done a bit of research I wonder if its the carbon brushes. If so how easy are they to replace/where are they? (Ihave checked plug fuse ok!) Thanks Jeremy