Look at the simple possibilities first. i.e. it obviously uses hudraulics, so check the fluid tank if full and there are no air-locks. Make sure the fluid hasn't been shaken before filling, I was once asked to get a bottle of brake fluid out the garage for my father-in-law. On the way back I was giving it a shake to mix up the different colours in the liquid. He went absolutely ballistic and threw it straight in the bin because I had introduced air bubbles into it. 
Check for leaks by putting dry cardboard underneath and checking every few days.
Sometimes people tend to overlook the obvious possibilities, (even experienced mechanics!)
Check for leaks by putting dry cardboard underneath and checking every few days.Sometimes people tend to overlook the obvious possibilities, (even experienced mechanics!)