My GA-Z77X-UD5H motherboard that is a little over a year old has developed several flakey problems. I got an RMA from Gigabyte and I'm going to return it tomorrow for repair (or replacement).
The problems that have developed over the last couple of months include flakey USB 3.0. On one of two ports Windows will see a USB 3.0 hard drive as OK and then turn around and flag it as needing formatted. On the other port it will flag it as USB 2.0. I've tried 2 different USB 3.0 interfaces (the one on my Coolermaster case front panel and a separate interface provided by Gigabyte with the motherboard) and they both react the same. The motherboard has 3 USB 3.0 connections, USB 1 and USB 3 work as noted, USB 2 works sometimes.
Other problems that have developed, the BIOS resets the power on time. I have it set to power on at a designated time in the mornings. The time will change from the set 5:30am to 5:03am. I've had to reset it several times. Resetting the CMOS memory and updating the BIOS has not helped. USB 2.0 has flakey problems with the keyboard/mouse ports whether wired or wireless. The DVI out from the motherboard port (using an i7 3770 Intel video) is dead (the VGA works).
This is also my recording studio system, although I do have a backup with a lesser CPU and memory that I can use if needed.
Wish me luck getting a speedy fix/replacement.
BTW, Merry Christmas and Happy New Year to all.