Without a photo being available in the spares list, I am unsure if this is the item I require to repair my machine. Does the switch operate in conjunction with the safety button on the top of the handle housing ? This safety button refuses to stay down when depressed and the handles held in, so the power is not being fed to the machine. I am not sure therefore if I need the 'main' switch and the safety button, or just the power switch alone. Your expertise would be appreciated.