depending on your cpu and ram and the mb bios it may or may not post. first off see if there a bios sticker on the mb to see what bios is on the mb. if there non start with the newest bios 1504. use the usb flash back port and rename the bios file z77st.cap put it on a fat32 usb stick into the white flashback port. with power supply off(in standby mode). press the flashback button and hold for a few seconds..it should start blinking...if the file is named right...the bios flashback light blink speed and pattern will change. when done the light will go out.; if the newest flash does not fix memory issue. check that the cpu cooler not screwed in to hard and bending the mb or cpu. also check that you have the 4/8 pin atx power plug near the top of the mb connected. if it is try unplugging the hard drive and cd-rom sata cables from the mb. there are two sata chipsets the intel ones and a 3party chipset if you put the hard drive and cd-rom into the wrong ones the mb may not post. also to degug your system pull the video card and use one ram dimm...i seen here and on rog where the mb has had dead ram slots. with 2 or more dimms in a bad dimm slot it wont post. last thing to check is bent pin on the mb under the cpu or the cpu not seated.
two things bad ram or ram that not been tested for that mb or the z77 chipset. see if it 1.5v ddr-3 ram. also check to see if it 1600 or slower ram. most 1600 ram should work. take a look at your video card make sure if it has two 6 pin pci that there both plugged in. with the ram clips on the sabertooth they take a little force to make sure then down and locked. i would use one dimm and the gpu and no other cards to see if you can get it to post. if you have another ps that rule out the power supply.
also what the model of the cpu. with new mb it called anti surge where there a small delay on cpu and case fans. it normal for the stock intel or aftermarket fan to spin up a few seconds after the on button is pressed.
is the 4/8 pin white atx cable plugged in. in on the top back edge of the mb. http://usa.asus.com/websites/Global/products/wMYmwl5uuG...
the 8 pin connector on the edge of the mb near the mb standoff screw and asus logo.
check that the video card in the top video slot...also try it in the lower one. i would also try another video card .
Same problem still happening. It's not the motherboard because I tried multiple, it's not the GPU because I tried multiple. The problem still happens when I turn the computer on I get 1 post beep and then LED's light up in all places.. not giving an accurate cause of the problem. I have gone through the troubleshooting guide, and have tried multiple RAM and tested the motherboard out of the case.
I have no idea what this could be, can someone give a clear explanation of this problem and what could be causing this so it can be fixed NOW... it has taken ages to actually find the cause of the problem.