Why is my HP Deskjet F4100 not turning on?

The most common cause is that the HP All-in-One is not properly connected to a power supply — ensure the power cord is firmly connected to both the device and power adapter and that the outlet is working. Another cause is pressing the On button too quickly; press it once and wait a few seconds as it may take a moment to power on. If it still does not turn on, it may have a mechanical failure and you should unplug it and contact HP at www.hp.com/support. (Page 10)