How to fix a PC that starts up then immediately shuts down?

Please follow the steps below to troubleshoot:

Check the power adapter is correctly attached to the PC and to the wall.

Note: Some of the models have power On/Off button on power supply, please make sure the switch is on.

Check whether monitor plug is correctly attached.

Please try to remove the power cable and connect back. Then, press the power button to boot up the PC again.