Hi I just build a new system and got some few issues the past days.
MB: Asus rampage 4 extreme x79 chipset
CPU: Intel I7 3820 @ 5 ghz
Ram: Corsair dominator gt 2000 mhz trichan (i know that is a bad decision)
Gpu: Gainward geforce GTX 680
Psu: Corsair AX1200 Gold
SSD: Intel 520 120Gb
So i first had some trouble booting, but i swap'd some places on the sata cabels and changed some places on the ram's, but eventually i got it running. So after a day with some gaming and surfing the computer just shut'd down, no warning no nothing.
And when it booted up again i was back to the problem i had i earlier + another issue, the computer did not find the ssd. So i was stuck with a boot issue and i had no hdd to start up the system with, i mixed again up the "swaping sata cabels and ram".
So after a while i found the ssd in bios and system started up again.
But now im back with the biggest issue so far, the usb ports, audio card, onboard lan card ect. aint working. My guess would be that the chipset have taken a vacation, but then again its weird that my GPU is still working.
I havent tryed to reinstall the computer yet to check if the driver has been corrupted or something.
on the missing devices sound like you or the bios turned off all the onboard devices in the bios. I would start by updaing the bios to the last bios file then going in and hit f5 put the mb back to factory default. I would look at the mb guild to see that the ram is in the right slots and that your ssd in connected to one of the red 6g sata ports. in the bios the sata port default to achi mode witch is the right mode for a ssd. you have to go into the boot screen in advance mode and make the ssd the first boot device. with the ram use cpu-z and look at the speed it runnning and use the spd info tab to see the rated speed of the ram.
to get the ram running at it rated top speed you have to in the ai part of the asus bios set the ram mode to xmp.
when you boot into windows with the right settings and it fine..start by downloading the intel chipset software from intel web page. if the chipset drivers are missing or damaged most of your onboard stuff wont work.
for the shutdown issue use hardware monitor to check your system temp and watch the power supply voltage..eather the gpu or cpu got to hot and the system shut down for safty. or the power supply has a issue when it fully loaded..most times it the cpu heat sink not on right or user forgets to put thermal paste on it.