I have had an intermittent problem with my z10pe-d16ws system with two Xeon CPUs that has driven my nutz for the last few months. The system failed to start one day with no warning and then sometimes started up for no reason. Working my way through the connections after the first hang, I noticed that the system LED was stuck on Qcode 67 (when booted and running it is AA). This Qcode happens when the drivers are loaded in memory before the boot sequence begins, and should be transient. Multiple message exchanges with the helpdesk guy Ethan at my system supplier jcns.com came up with no real solutions other than to check connections and reset the bios. Yesterday the hang at Qcode 67 happened again. I reset the bios with no effect, so if you've spent a lot of time adjusting the bios clocks you might not want to start with this. I popped and reinserted all the memory chips with no joy. Then reasoning that the drivers are going into the first memory chip, I swapped the A1 bank chip with the C1 chip. Success! So if this happens to you, suspect the first memory chip first before trying anything else (and I had tried everything else before getting here - lots of time wasted).

UPdate: not solved. Qcode 67 returned. Swapping memory chips around did not help this time. Back to square one

I was chasing the wrong problem but somehow memory is involved because I can get the system to start by swapping around the memory. I pulled out all memory sticks (8GB each) and got the no memory beeps. Put in two sticks, one for each processor. Booted once. I put all 8 sticks back in and got the b7 Q-code, which corresponds to "Configuration Reset (reset of NVRAM settings)". This caused me to USB reflash the BIOS with the latest ASUS version. Then things started working differently, but not perfectly. If I put any more than 2 sticks in, it would hang.
Then I noticed that the boot up screen said that the RAM was DDR4-1333 not 2133, which is what these sticks are. On the next boot, I changed the bios RAM frequency to 2133, and now the bios startup screen says it is 1833, so at least better but not accurate. Now I have 4 sticks installed and it is working. Not clear to me why things worked the way they did. I will eventually install the remaining 4 memory sticks to see whether it is all working correctly.
So it is working, but I have a sneaking suspicion that I don't have the problem solved.

Hey isopodz! I know it's been some years since you posted this issue, but do you have an update? I have a similar issue with my z10pe-d16ws, which has been running fine for a few years. Now the server hangs daily with Q-code 67/B7 and symptoms similar to yours.

Yes,the problem turned out to be the memory chips. I have had at least one chip that was interfering with the boot process. Memcheck did not see any problems, unfortunately. I fixed the problem by pulling out memory chips until it booted and then putting chips in until the boot process failed. I put in two chips at a time thinking that the memory had to be the same for each processor. Thus I have two chips that are suspect but I didn't continue to swap those two chips to find out which was bad since I wanted to have the same number of chips for each processor and my memory requirements were not great enough to justify buying new ones. This process was ad hoc and somewhat tedious. A better way to do this must exist but I'm not that good with electronics (but swapping chips is not a problem).

Speaking of swapping chips, last year Ebay had used mid-high range chips compatible with this board under $300 each so I upgraded my slow single-thread chips for 8 core dual Xeon E5-2667 V4 3.20GHz. No problems with the chips and now I smile whenever I boot the workstation - happens much faster now.