I have suddenly come across this problem. I've used the board (Z77X-d3h) for about 2 years now with no problems at all. Recently, it began to have issues shutting down. In fact, it wouldn't shut down at all and would just keep rebooting once I selected shutdown. So, I turned it off at the PSU. I took the MB out and stripped it down to just the memory, GPU, and my SSD. It turns on and off perfectly and seems to work just fine. As soon as I plug in the front USB connectors to the MB it won't post or show any signs of power. Once I unplug the connectors and reset the CMOS, it starts up just fine. I did update the bios successfully and it still does the same thing. I have updated the drivers from the Gigabyte website too. I also changed the battery in the MB as well. Do you think it could be the MB or could it be a possible short in the wires from the case? Thoughts?
Thanks in advance for any suggestions.