Z77X-UD3H won't wake from sleep

[Uncle_Steve]

I have a GA-Z77X-UD3H rev 1.1 which won't wake from sleep. I've tried
both Win 7 and Win 8 with the same results: the fans spin up but I
never get anything on the screen. The LEDs show codes 19 and 03
cycling repeatedly.

Any suggestions?

[Bullcalf]

I heard that there were several experiences from US users who used PSU having evergy-saving function to limit its standby power under 1 watte about 5 min OS shut-down. as far as I know, to boot, there should be over 1 watte power on +5Vsb for some gigabyte motherboard.

So, you'd better try to boot the motherboard juster after OS shutdown wheterh it could boot then isolate your problem.