Scenario 1, cause 1: No Power

First check if the PC is well connected to the power. Firmly press on both sides of the power cable to make sure the cable ends are completely inserted in the power socket and the PC. Also check if the power socket actually has power to it. When in doubt, try to connect to another power socket or connect a lamp to the power socket to test it. Another thing to look for is that there is no power switch on the back of the power supply and make sure it is set on “1”. Look for an example here:

Also check if the power supply is set for the correct voltage. Most of them have a red110/220 Volt switch. The 220 volt setting won't work in the U.S.A., the PC will do not much.

In Europe, you will notice when this switch is on 110V and you connect it to a 220V socket, you will probably smell something is burning. Check out this video what happens :-)