Hello, I am having a problem with my computer shutting down. Whenever I try to shut down, everything goes normally until the part where the computer components stop receiving power. All the fans keep humming along and the lights stay lit, and never shut down unless I hold the power button for 5 seconds or so. My monitor shuts down after going through the displays that are normally shown in the shut down process.
I tried disabling all startup processes, thinking that something was causing a hang, but the problem persisted.
I recently installed new components: a CPU, CPU heatsink, and video cards.
Usually there are a number of setting in the BIOS like "Wake on _____". Wake on PME, Wake on LAN, Wake on about 6 other things. Make sure they're all disabled. They all tell the computer to power back on when it receives some external cue, which in the above cases is probably happening constantly.