The Kogan Cold Press Juicer, and the Kogan 3-in-1 juicer, will only function when the lid is locked correctly.
This is a safety feature of the juicer, to ensure it cannot be used when it is not correctly assembled.
If you find that your juicer will not turn on the first thing to check is that the bowl is secured properly to the base. It may seem like the bowl has been inserted correctly, but if it is not completely in, and the arrows do not align, the juicer will not start.