I had similar problem with this MB and the problem turned out to be a usb memory stick left in the front socket. For some reason the bios was try to boot from this, just pulling it out fixed the problem.
If it is a memory problem try removing some of the modules to see if you can find the faulty one.
Double checked and no usb stick was found.
I will finally start removing memory sticks and see if one of them became defective.
But let's see if others have some thoughts.
Particularly confusing is why the MEMOK! button won't do its memory testing -- it should start Flashing after I press the button -- but it stays solid, even after Windows reboots -- which (according to the manual) it should do a series of memory tests.
Anyway later today I'll remove the memory and, I guess, put one stick at a time into the system and see what happens.
Or should I put at least 2 sticks at a time,
I have 24 GB of memory in my 6 memory sticks.
Well I fixed it.
Not sure exactly what I did that fixed it, but here is what I did.
1) I unplugged the computer.
2) I disconnected the power supply from the motherboard.
3) I removed the battery.
4) I let it sit for about an hour.
5) I pushed the motherboard reset button on the back of my computer (I perhaps should have done this first, but I did it.)
6) I put a new battery into the motherboard (perhaps the old one was dead or a zombie.)
7) I reconnected the power supply to the mother board.
8) I plugged in the box.
9) I heard the familiar two beeps, and sure enough the unit booted up.
Upon bootup the ASUS screen had me to into bios and double check everything. Then it all rebooted again, and opened windows 7.
I will make sure I have the lastest ASUS bios. But I see that it is recognizing all 24 GB of memory, so I guess I am good to go.