I would push hard on the button(s). They have a tendency to stop making contact after infrequent use. If it doesn't help, you'll have to have the computer opened by a specialist.
PS My predecessor also had the same problem with Canon.
Greetings, Mr Gretler.
Please contact customer service directly regarding questions and support for your order. Either you ordered the product without a power supply unit or the wrong product was delivered to you.