What should I do if my HP Z440 Workstation won't boot or has no power or video?

First, check that the workstation and monitor are plugged into a working electrical outlet and verify that both power lights are on. Check all cable connections for loose or incorrect connections, and try waking the workstation by pressing any key or the power button. If the system remains unresponsive, press and hold the power button for at least four seconds to shut down, then press it again to restart; if it still won't shut down, unplug the power cord, wait a few seconds, and plug it back in. (Page 34)