Z77-UD5H won't POST, debug LED = "C "

[Vain]

I am using this with a Core i7-3770K.  When I power up the board, the fans come on for about 2-3 seconds and then turn off.  The debug LED flashes "C " for half a second.  I also saw the red light "m_bios" flash for a quarter of a second.   Unfortunately, in the manual error code "C " is not described, as it is in the "Reserved" range in the appendix.  Does this mean I have a dead CPU, or something else?  I've tried disconnecting and reconnecting everything, keeping the minimal number of things connected, but no luck.

[Dark Mantis]

Hi and welcome. My first thought would be thatb the BIOS on your motherboard at present isn't supporting the processor. The motherboard number that you have quoted doesn't exist so I am assuming that you actually have the GA-Z77X-UD5H. If I am right then your CPU would require the motherboard to have a BIOS of at least F6. See here:

http://uk.gigabyte.com/support-downloads/cpu-support-popup.aspx?pid=4139

If it hasn't you will need a supported processor to run the upgrade or take it to a shop that can help you.

[Pmatthews05]

Vain, did you ever get this working?

I've just brought the GA-Z77X-UD5H and the I7 3770k. Powered on for the first time last night, and the LED for the bios were alternating, and the motherboard code displaying looks like a C.  My motherboard picture http://twitter.com/mrpmatthews/status/234790699676078080/photo/1/large
It seems to be the same problem you were having. Did you do what Dark Mantis said and obtain a processor that works with a lesser BIOS?

If this is true, it's annoying as I've only just brought this motherboard, and you would expect them to ship with latest BIOS.

[emcardelli]

I have the same problem, I try every think. Only I won't to try this:

http://forum.giga-byte.co.uk/index.php/topic,9438.0.html

Other similar problem:
http://forum.giga-byte.co.uk/index.php/topic,9362.0.html

I startup the PC only COLD boot. If I wait a few minutes with unplugged the psu, boot properly.
If I don't clear CMOS, I have the debug code 19 and boot loop.
I can't try with other psu because I don't have one.
My system:
GA-Z77X-UD5h
I5 3570k
2x 4gb Corsair Vengeance 1600 c9
PSU Coolermaster 1000w http://www.coolermaster.com/product.php?product_id=2519

[emcardelli]

I can solve this problem with changed the PSU. I try with Termaltake toughpower 650w 4 rails and I purchase a Corsair hx750w with 1 rail.
I think this mother need to much power on 12v rail, more than 16 efective Ampere!!