ok thats an easy one for me,the one click you can hear is the starter relay points contacting inside the yellow box(four wires to it )2 big 2 small.the two big ones are one from the battery and the other to the starter motor the 2 small ones are an earth and a live triggered by the start button.so basically the realy is working ok and joining the two big wires together inside whcih should send the power straight down to the starter motor which is under the bike near the stand.so the problem is either the live wire coming from the relay(yellow box) to the starter motor is either broken or has a bad connection one one of the ends (usually the starter motor end) or the starter motor is funked.try tapping the starter motor while the start button is being pressed.
adam bike doctor(of milton keynes motorcycle centre), October 2010