Maximus X and Maximus XI (Hero)...will not post with memory in A1 or A2

[Benny]

I have a Maximus X Hero w/ i7 8700k and two sticks of 16GB G.Skill PC 3200 kit (listed in QVL for both motherboards).

System would only post with the modules in B1 or B2, and since dual channel configuration requires A2-B2 (or A1-B1), I'm stuck running both modules in single channel. Anything in an A slot results in code CC and post failure. The exact same processor and memory are resulting in the same problem on a new Maximus XI board.

I have followed some troubleshooting steps shared by techs on the Asus forums to no avail, including various BIOS tweaks and voltage settings. I've examined the pins on both motherboards and can see no damage, nor do I find any on the cpu itself. Also, I've attempted to post with the gpus taken out, motherboard screws loosened, and the cpu cooler just resting and not screwed in. Same result.

And unfortunately I don't have extra modules lying around, but have ordered a couple of sticks (also listed in QVL for both boards) which will be here Monday. However, since my modules work fine in single channel mode (B slots), I'm inclined to believe they're fine.

Until I'm able to troubleshoot some more, my question is: could my cpu be causing this problem? Because I've had NO other issues with it. Runs stable and seems fine. I've run intel diagnostic tests on it and everything passes, though I don't know how much stock to put in that. But two different motherboards? Hard to believe they'd both be bad with the exact same issue...

Anybody have any experience with this problem...is there something else I might be missing or could try?

 

[trents]

RMA the motherboard.

 

[Benny]

RMA the motherboard.

The exact same processor and memory are resulting in the same problem on a new Maximus XI board.

 

[Johan45]

I agree, may not be that simple. You won't be able to tell if it's the memory unless you try different sticks. Have you made any changes to the cooler? It's possible the CPU doesn't have enough pressure to make proper contact with the pins.

 

[Benny]

I agree, may not be that simple. You won't be able to tell if it's the memory unless you try different sticks. Have you made any changes to the cooler? It's possible the CPU doesn't have enough pressure to make proper contact with the pins.

I've tested with the cooler off, with it on, with it on and the screws loosed, and with it simply resting on top of the cpu. Always the same result.

And I've tested both boards the same way.

With respect to memory, I agree. On Monday I'll know more after I try new modules, but in the meantime my question is, can the modules themselves be defective to the point they would refuse to work in the A slots on multiple boards (while still working in the B slots)? Is that even possible? I can't put just a single module in A1 or A2 and get the system to post. (and A2 is recommended as the primary slot for a single module).

Thank you for the input.

 

[Johan45]

It really does sound like either a MB or CPU issue. What were the circumstances that led to this behavior? Did it just up and quit one day? Is this a new build? I find it highly suspect that 2 motherboards have the same problem

 

[MaddMutt]

I'll throw the weird option to think about...
IIRC the i7-8700k has 2 IMC's and the i9-79xx/99xx/109xx has 4 IMC's. <- If this is correct, COULD this be a CPU problem???? This would explain why only slots A1/B1 work and not A2/B2...This would also explain why the problem continues from MB to MB as the CPU's IMC is bad..

^ This is just my opinion BUT it is something to think about

 

[Benny]

It really does sound like either a MB or CPU issue. What were the circumstances that led to this behavior? Did it just up and quit one day? Is this a new build? I find it highly suspect that 2 motherboards have the same problem

The Maximus X is a year old, and I initially had this problem from day one, but due to necessity I just used the B slots and forgot about the issue since everything else ran so well. (Now, of course, I regret not getting to the bottom of it right then and there.)

In any case, recently I was reading about the issue and decided to revisit. After trying unsuccessfully to get the system to post in dual channel, I figured the motherboard was defective in some way, so bought a new one and was going to see if I could get the old one fixed and pass it off to a family member who could have used it. But I got the brand new Maximus XI, installed the same cpu and memory modules and had the exact same problem from the start.

So both boards have performed just fine (no freezing, crashing, overheating, etc...) but using the same cpu and memory modules (and psu, for that matter), the A slots are not recognized in either.

I've inspected the cpu for damage...can't see anything out of the ordinary, and it seems level. Checked the socket pins in both mb's and they look okay to me as well. The cpu, if it's bad, is still under warranty, if I can convince Intel of the problem. I've never returned a processor under warranty before...no idea what to expect. In any case, I'm going to take it and the memory into a shop next week and see if they can test them out separately in different boards.

I'll throw the weird option to think about...
IIRC the i7-8700k has 2 IMC's and the i9-79xx/99xx/109xx has 4 IMC's. <- If this is correct, COULD this be a CPU problem???? This would explain why only slots A1/B1 work and not A2/B2...This would also explain why the problem continues from MB to MB as the CPU's IMC is bad..

^ This is just my opinion BUT it is something to think about

Neither A1 or A2 work...

I only have B1 and B2, and for Asus you need either A1/B1 or A2/B2 for dual channel.

 

[MaddMutt]

If you haven't De-Lidded the CPU -> warranty voided <- I would submit the CPU back to Intel This is a classic case of one of the IMC's in the CPU has failed. There will not be any damage on the outside that shows this. Submit the RMA to Intel stating that one of the IMC's is bad on the i7-8700k. You will also need to list any trouble shooting that you have done (If not -> you will receive multiple requests to do this and that to fix the problem). State what memory you have and what memory slots work and don't work.
I had this happen with my i7-8700k but I had De-Lidded it so I accepted the blame. I also killed my AsRock z170 OCF in the process too
It should not be hard to RMA the CPU, just make sure you have not voided the warranty on it
I have also found it very helpful if you tell the truth (No matter how weird it seems) up front I have RMAed 2 i7-5960x's - One had a BAD contact pad (square on bottom of cpu) and the other was from a ESD damage - both were replaced by Intel with a NIB processor.

 

[Benny]

Thanks...that's helpful info. If the IMC failed then it shipped to me that way. It was brand new along with the first motherboard. Would it be helpful to my case to take it in to someone local and have it tested...or would that also void the warranty somehow?

 

[MaddMutt]

You can do both Just make sure that the numbers/information on the IHS does not get rubbed off. I would take the MB and CPU to a friends house and let them check it. You want to start with a known GOOD CPU, MB, & Mem. They should install their GOOD CPU & Mem in your MB to verify that it is working correctly. They should also install your CPU w/ their Memory in their MB (The CPU will not mess up their MB) and verify the CPU. If that checks out, install your CPU & Memory in their MB and see if the problem comes back. I would say that it's the CPU's IMC that is the problem. The very fact that both MB's will not run the memory in any A1/A2 slot (single or dual) points the finger at the CPU's IMC

 

[trents]

Missed that part about the same CPU and memory produce the same problem on another known good motherboard. But since all the memory modules work individually in all the slots I would think it would have to be that the CPU IMC is bad.

 

[Benny]

I'd like to thank everybody that helped me out with my problem. Turns out it was indeed the IMC on the processor. Tried a new processor in both motherboards and dual channel memory works without a hitch. Thankfully, the cpu is still under warranty, so I am going to try to get a replacement from Intel.

Thanks again. You guys were a big help.

 

[MaddMutt]

No Problem I know you purchased the new MB to fix the memory problem. Do you still have the option of returning it??

 

[Benny]

No Problem I know you purchased the new MB to fix the memory problem. Do you still have the option of returning it??

Don't need to return it. Got a family member that's willing to take it off my hands. So, no worries there!

 

[WhitehawkEQ]

I've tested with the cooler off, with it on, with it on and the screws loosed, and with it simply resting on top of the cpu. Always the same result.

I know I'm a day late and a dollar short on repelling to this post but NEVER NEVER NEVER power the PC with out a cooler on the CPU. Don't matter if it's for a short time or not, I had a friend years ago who had a HS fall off the CPU (it was on lose), and before the HS hit the bottom of the case (about10 inches) the CPU fried (fire and smoke and melted black socket). So please for your safety don't remove the cooler.

 

[trents]

CPUs catching on fire was a phenomenon way back when. There are actually Youtube videos of people doing it on purpose. Although I certainly do no recommend powering up a rig with no cooling on the CPU it is also true that modern processors have thermal overload protection that actually works pretty well and in many or most cases will prevent permanent damage to the chip.

I sold a used desktop to a customer last year that had a first generation AMD quad core in it, probably a 2008 vintage CPU. The plastic retention bracket broke and the cooler fell off. It caused it to boot loop. I replaced the bracket and reinstalled the cooler and it worked just fine.