Žilavý P.: Misbehaving Electrostatics II, Fair 22, Olomouc 2017The school Van de Graaff generator is one of the basic school instruments used for electrostatics experiments. Nevertheless, the principle of its function is often a little bit of a mystery to many people. How does it really work? How to look for the fault when it doesn’t work properly? An unusual way of looking for the answers to these questions with the use of a digital oscilloscope with a high-voltage probe is the content of the paper.