What processor do you have installed? What memory do you have installed? (part numbers please) What storage devices do you have connected? (again, part numbers please) What USB devices do you have connected? (again, part numbers please).
Please write down (or better, take a video) the POST Code sequence that precedes this hang.
Something to try: Disconnect system from A/C power, press and hold system's power button for 5 seconds, remove CR2032 battery from board, wait 15 minutes, reinstall battery and then reconnect A/C power. Does this change what happens? If the system is betting beyond hang, use F2 key to enter BIOS Setup and then set the date and time.
Hope this helps (let me know),