Z270G does not post when DIMM_A1 and DIMMA2 sockets used.

[Sp1]

Hello everyone,

I have next problem with my Asus Z270G motherboard:
When I use DDR4 DIMM_A1 and DIMM_A2 RAM slots it won’t post, not even in to UEFI.

Here are the sockets numbering for reference.


I am using 2 sets of G.Skill DDR4 Trident Z RGB modules. In total 4 modules at 32GB.
Thus 2 sets of G.Skill F4-3000C16D-16GTZR. These where in sale so it was cheaper than a package with 4 modules, that’s why went for 2x2 sets.

I am on latest 0906 BIOS, first I pulled all ram modules out and used recommended memory configurations, whenever I put something in A1 or A2 slot the board wouldn’t post and give yellow LED DIMM error warning. Only slots B1 and B2 are working, I have installed windows and everything works fine, I also turned on XMP and that’s working too on 3000MHz. To make sure that every single RAM modules works I tried them individually on B2 and then B1 slots. All RAM modules are working.

This is a new build with following parts:
https://pcpartpicker.com/list/NNGrhq
Here a list of important parts, if you don’t want to check the link:
Asus STRIX Z270G Micro ATX
Intel Core i7-7700K
Cryorig H7 CPU cooler
2x G.Skill TridentZ RGB 16GB (2 x 8GB) DDR4-3000 in total 32GB
Samsung 960 Evo 250GB M.2-2280 Solid State Drive
XFX Radeon RX 480 8GB GTR Black Edition Video Card
EVGA SuperNOVA 650W 80+ Gold Power Supply
Thermaltake Core V21 Case
Microsoft Windows 10 Pro 64-bit

Nothing except XMP is overclocked (YET)

Did anyone experience same problem with different RAM modules?
I would really appreciate if someone could help me with this issue.

Here pictures of the build:

[Sp1]

Okay, I just got a reply from Asus support center Netherlands, and they tell me that my memory module is not in the QVL list and probably not supported.
It is indeed not in the QVL list but I am not sure if that's issue:
https://www.asus.com/Motherboards/ROG-STRIX-Z270G-GAMING/HelpDesk_QVL/

G.Skill number is F4-3000C16D-16GTZR
But if it was the memory why does it work on the other slots except 2 closest to the CPU.

Anyone else using this memory from G.Skill?

[Chino]

Have you tried using a single module in any of the two slots that you mentioned without populating the others?

As a sidenote, you shouldn't be combining memory kits even if they are identical. You're only asking for problems.

[Sp1]

Hi Chino, Thanks for your reply.

Yes indeed I have used all slots one by one with a single module but the mentioned sockets wont work.
You are right about mixing the memory kits but I even than this is not the issue at the moment, I wish it was than I knew what to do 🙂
I mixed memory modules before to be honest and never got problems with it, but it is possible to get issues.

My vendor asked photos of the CPU socket, they also asked me to fill in a RMA to be sure.

[Chino]

Sp@wn wrote:


Yes indeed I have used all slots one by one with a single module but the mentioned sockets wont work.

Try loosening the screws for your heatsink a little. If that doesn't work, then proceed to remove everything from your case and examine the CPU socket for any bent or missing pins. Report back your results. 🙂

[Rawkhound]

I have been having the same memory problems with my Maximus IX Formula/tridentz ddr-400 pc4-32000 8192x4 memory kit with the A1 and A2 DIMM slots not posting with any memory installed. ( and yes the memory is on the QVL for my mobo)...I have done a lot of RAM troubleshooting and so far the only work around I have come up with is to disable my A1/A2 slots in bios in the DRAM timing settings which will then let my system post. It is strange that when I use my CPU-ID it states that I have all 32G of memory in but my Task Manager is only using 16GB ....will keep tweaking things here as well

[Sp1]

Thanks for the replies 🙂

@Chino, I already loosen the screws of the heatsink, but I will take the CPU of tonight when I come home. I wil examen it, I have a electronics bench at home.
I work a lot with electronics, I also reflow chips of laptops and some PCB's at work 😄 If there is something wrong with the socket I should be able to see.
My home lab:



@Rawkhound, thanks for letting me know, at least I know I am not alone.

I also checked G.Skill site and my motherboard is not in the QVL there either, there is not even single Asus motherboard:
https://gskill.com/en/product/f4-3000c16d-16gtzr

This one should work with my motherboard:
https://www.gskill.com/en/product/f4-3000c15q-32gtzr

But after reading Rawkhound's problem I dont know what to do, I will try to replace the modules first if my vendor agrees.

[I_G_SYME]

It would appear from reading posts over the last few days that to give yourself a fighting chance you must use RAM on the QVL list. Having said that, if you indeed have tried one ram module at a time in every slot and posted and run say MEMTEST 86 (or a program of your choice) with no problems...... then it would point to me to be an RMA on the board.
Glad to say my Z270 G has run flawlessly but I only have two sticks of ram. Getting 4 sticks of ram to run flawlessly was always a tricky balancing act as I seem to remember on my build from 5yrs back with 4 sticks of DDR3 ram.

[Chino]

Nice lab indeed. 😮

[Sp1]

Guys thanks for the replies again 🙂

Well, I am little ashamed… I should check this before but some facts mislead me when testing so didn’t think about CPU socket.

I took some pictures of the CPU socket under a magnifier and I saw one socket pin little off its place, just a little touch and it jumped back to its position, now all 4 DIMM slots are working.

So stupid of me for not checking, I hope my mistake will help others.

@Chino, thanks for pointing this out 🙂

Here is the pin, sorry about the picture quality, there was a big magnifier glass with light between the camera and socket.