Hi all, I've spent the last month with ASUS trying to resolve this problem that crept up roughly one month after I'd completed my system build.
Motherboard - Asus Maximus X Hero Z370 Wi-fi, BIOS v 1602, with previous versions tried. CPU - Intel I7 8700K 3.7 GHZ 12MB Cache LGA 1151 Memory - 4x Corsair Vengeance RGB 8GB DDR4 3600 PC4 28800 - CMR16GX4M2C3600C18W OS Drive - Samsung 960 Pro 512GB M.2 Performance Storage = Samsung 800 EVO 1TB 2.5" SATA SSD Optical Storage - Pioneer 16x Blu-Ray/DVD Writer Bulk Storage - Seagate FireCuda Gaming SSHD 2TB 7200RPM 64MB Cache SATA 6 Video - EVGA GeForce GTX 1080TI Power - Seasonic 750W 80+ CPU Cooling - Corsair Hydro Series H150i RGB OS - Windows 10 Professional X64 APC 1500w Battery Backup
The system operated perfectly for about a month with all banks full, using 32GB of memory, one day, with no obvious reason, the system would not POST. After extensive troubleshooting, I found that if memory slots A1 and A2 were left unpopulated, the system would work with no issues. Swapping memory sticks around revealed that all of them were fully functional, but no amount of effort would allow A1 and A2 to be populated (also neither could be populated on their own.) I did some closer inspection of the motherboard looking for physical damage. I noted some slight discoloration near the RGB header nearest the Q-code display (and the memory of course) that might have been the result of some kind of short. As nothing had become disconnected, I could find NO reason for this. The discoloration was even more visible on the back of the board.
I reported all of this, among other information obtained by following their troubleshooting requirements for RMA. I stressed that the discoloration seemed a likely reason for this to have occurred. I received the RMA notification/authorization and immediately un-installed the motherboard, carefully. As I prepared to pack up the board, the CPU cover slipped while I was re-installing it for shipping, resulting in a few bent CPU socket pins. This error cost me $75 and seems to have distracted ASUS from the actual cause of the problem. I tried time and again to re-focus the issue to the discoloration and not the CPU socket damage (which happened AFTER the fact) and hoped for the best.
I received the replacement (used) motherboard, I know that it's a different board due to the serial number. Unfortunately the problem persists. I am concerned that the board may have caused some damage to the CPU or, hopefully, it's just the same problem carried over to the other board. My hope being that this replacement board had a similar problem to the original.
Has anyone else managed to defeat this problem? I've found that several people have had the exact same issue (to include the replacement board issue) with the Maximus Hero IX board.
I have not noticed any discoloration, though to be honest I haven't looked too hard yet. I can't see how the same problem could've been on different boards unless there was a manufacturing defect.
I'd love to hear any helpful ideas, I certainly don't want to give up half of my memory for no good reason.
I have the same issue with a Strix Gaming-I mini-itx motherboard, running DDR4-4133.
With one dimm in the slot furthest away from the CPU, the system will POST, but if I add the 2nd dimm to the slot nearest the CPU, it attempts memory training and then fails after three reboots, with the orange dimm led illuminated on the motherboard. Tried different memory speeds , 2133, 2166 and more voltage, 1.35v and 1.40v but nothing helps. Memory is good, tried it in another motherboard (Gigabyte). Had the exact same issue with an Z370 Strix board and I thought the board was damaged in some way and sent it back and got the Z380 version, but seeing the same issue there also. It's definitely a BIOS issue with memory profiles provided by Asus. Never had this issue before on any other board, which mainly were Gigabyte until now....regretting the decision to try Asus.