If it were me, I'd take a look at the power supply
I have had one mobo failure since the early 1980's and that was with a 5+ year old one. I have had multiple PSU's fail. From my experience I would say that the chances you have two diferent brands of mobo's fail only weeks after each other are very, very slim. I agree with Jim that you should have a closer look at the PSU.
Did you check the various rails with this calculator: http://extreme.outervision.com/psucalculator.jsp
BTW, it is advisable to get the Pro version which is extremely cheap and gives you lifelong access to the latest version and shows you the requirements on the various rails.
The original PSU i got two weeks ago for the new system is a PC Power & Cooling (PP&C )910 watt unit. I think thats plenty of power. The PSU tester diaplays the following:
+5V = 5.3
-12V = 12.2
+12V1 = 12.3
+12V2 = 12.3
+3.3V = 3.4
5VSB = 5.3
P.G. = 300ms
I plugged the PP&C 910w PSU as well as a completely different 400w PSU into the GA-EX58-UD5 with the following components removed - no drives, cards or case fans and all drive/audio/usb connectors disconnected - just the i7 920 CPU and ram - the mb acted in the same manner. Actually, its the PSU that's reacting to the motherboard i think. I can hear both PSU's "click" like its tripping a breaker then resetting - hence the mb starting and stopping.
Anyway, after i removed some and then all of the ram, the system started without stopping but still no post. I have also been getting a debug error code of 62. From what i understand, the error code indicates that the motherboard is not recognizing the ram.
It would appear that your both wrong in this case.
I searched the internet and found some posts where either the bios has to updated to accept ram i have or the ram has to be replaced with something the GA-EX58-UD5 likes. In one post, the current ram, Crucial DDR3 1066 (thats what i got), was replaced with Corsair XMS3 1333 ram and the system booted up.
I'll keep you updated.
Oh well... 2 different MB's and (presumably) the same PSU was worth a shot
It really SUCKS that memory modules can be so sensitive to "whatever" that they work in one MB and not in another
My future spec is for Asus P6 and Crucial 1066 ram, so when I get closer to my actual build date, I'm going to have to do some Googling for that, or other, combinations
Due to my miniscule budget I am buying when Newegg has components on sale... but I'm going to buy MB and Ram and CPU all together, at the last minute, just in case something doesn't work together and I have to do a return (I've built a half dozen computer over the years, for myself or relatives, with never a problem... but there's always a first time!)
unfortunately, its not like the old days when you could just about mix and match anything and it would work. The newer processors and this DDR3 ram seem to be making things a little more difficult. It would not surprise me if it has more to do with the bios not being updated to support a wider range of the new DDR3 ram.
Ok, i figured out the problem with the repeated start/stop (cycling) without posting.
I my case it's either a bad stick of ram in one of the two sets or the bios just doesn't like that stick. I rotated out each 3x2gb ram set in slots 1/3/5 until i found the problem set that caused the system to cycle. I then rotated each stick from the problem set with a stick from the good set and attempted a reboot until i identified the bad stick.
Since i wanted to make sure the problem was not a bad slot, i placed each individual stick from the problem set into slot 2 until i confirmed that the same bad stick caused the system to cycle without posting.
Now, i just hope Newegg will replace the problem set even though i don't have the original packaging anymore. If not, i guess i'll buy another single stick.
Thanks for reporting back and I hope they will exchange the stick or kit for you.
I usually keep the original packaging just for these situations and then, years later, when cleaning up, I throw them all away.