well my pc still do POST fine so my keyboard works since i didn't get any keyboard error beeps but i've already tried another keyboard and it still stuck and keys don't work. also tried without any peripherals hooked up and it's still stuck.
Have you tried a different power supply, it could have a weak voltage somewhere.
The only other thing to try is to remove the battery. Leave it out for a couple of hours, overnite if possible. Re-install the battery and it might work, I've seen it happen before, recently even
But it sounds like it's time to RMA the mobo to me.
try to pass the GIGABYTE logo by pressing the Tab key & see where it is stopping ..
keep pressing Tab key after the keyboard's lights blink ... this should remove the post logo & show the real post .. tell me where it is stopping ..