I received the mission of buying parts and putting together a computer for a friend of the family.
Core i7 950(3.06G,L2:4x256KB,L3:8M, rev.D0,130W)
ASUS Sabertooth X58
6GB of Corsair XMS3 3x2GB
GeForce GTX 570
Corsair GS700w power supply
Cooler Master CM 690 II
Western Digital 500GB SATA
Everything is in there nice and snug, cables have been connected and hidden as best as possible.
Currently the machine does not have an operating system, because the DVD drive did not arrive yet.
When I turn the PC on, it boots nice and tight, then after 5 seconds, it turns off. Now this would be a standard issue of not enough power, or dysfunctional/misplaced RAM, but here is the weird part. After shutting down, it turns on again by itself, runs for 5 seconds, turns off one more time, turns back on one more time by itself, and THEN it runs as it is supposed to.
So I press the button, it turns on, shuts off, turns on, shuts off, turns on and runs properly all by itself.
I am, however, able to access to BIOS when it finally does keep running, and in the BIOS it says it only registers 4GBs of RAM.
There are six slots on the MOBO for RAM. [+] is an inserted RAM stick,  is an empty.
Here is how they are placed.
[+] [+] [+] - which should be the A1 B1 and C1 as shown in the MOBO manual.
If one stick of RAM is removed, the machine boots properly the first time it turns on.
All power cables are firmly placed, everything is double-checked, I am ruling pwsupply out.
As mentioned, Windows is not installed, could be it?
Perhaps an outdated BIOS/Incorrect voltage settings? Even though you really shouldn't encounter problems with incorrect voltage, as the machine will be running factory settings.
Any ideas? Switching the RAM sticks around didn't help much, perhaps using the right side of the RAM slots will do anything?
it could be that the kit not on the mb qal list. it could been a quick kit that came out for for the x58 but was never qual for 3x channel but works fine in two channel. sometime on the x58 mb you have to check the timming or spd value the mb has read for the dimms and see if the voltage is ok. sometime you have to bump the voltage up.
Check the system using 1 stick at a time. First in the first slot; if it runs ok move the stick to the next brown slot and so on. If it runs ok these 3 times then you know you have 1 good stick and 3 good slots. Rinse and repeat with the next stick using only the first slot. If all the sticks test good start over using 2 sticks then three. If all three sticks test good but still do not work when all are in place, boot to the bios and check that the memory voltage is set to 1.65 or the closest increment. It could be that the default voltage is not correct.
I had the same kind of issue when i made my computer with a Sabertooth X58. I though it was the ram because the red light leaded me to that conclusion
I figured out later that it was the harddisk options in the bios IDE/ATA and i had to put it to ATA...
In some other system, you'll get a blu-screen or whatever, but with this one you have a complete shutdown, at least thats what i had for having it left to the default IDE
Since it would immediatly shutdown, i had to put the jumper on the motherboard to reset the bios and have access to it on the next boot