2nd NVMe caused...DRAM issues?

[LakelandHokie]

I very recently was able to finally build a killer rig (specs below), and initially started with a 2TB NVMe.  However, with some prices being pretty darn low, decided to get a second SSD, and with sales went with an ADATA M.2 2880 Gen4 2TB drive.

 

Before installing this new drive, everything worked beautifully, without any issues at all.  However, after carefully removing the 4090 to access the M2_2 slot, the system wouldn't boot, with the motherboard showing a steady DRAM light.  Any ideas what could have possibly caused this?  While I've built computers before, I really haven't messed with that in about 10 years, outside of a couple of video card upgrades.

 

Testing out the RAM showed that they were fine, however it took me basically taking everything apart except for the CPU at least 4-5 times, testing all of the DIMM slots, etc, and then (with the new SSD removed, though it had been for awhile during troubleshooting at this point) it randomly booted to bios and is working as it was before (BIOS is the default shipped BIOS).  I'd like to have the extra storage space, but am at this point extremely leery about trying to stick that NVMe back into the system.  Any ideas what could have possibly caused this issue?  Thanks for any insight!

 

CPU: AMD 7800X3D

Motherboard:  ASUS TUF Gaming X670E-PLUS WiFi

RAM:  G.Skill Trident Z5 RGB 2x32GB DDR5 6400

GPU: ZOTAC Gaming 4090 AMP Extreme AIRO

SSD: WD_BLACK 2TB SN770

PSU: EVGA SuperNOVA 1000 G5

Cooling:  DeepCool LT720 AIO

[Bjoolz]

The debug lights are not really errors lights. They show you which part of POST the board is currently doing, so if it gets stuck on one that's where you begin looking. So it's not really telling you that there is a problem with RAM, it's getting stuck testing the RAM during POST. If you have the same issue with multiple individual sticks then it's not RAM causing it. It could be the board or even CPU (I know it's not in this case, just in general). It could be a bad M.2 slot. NVMe drives use PCIe which often feed straight into the CPU (On AMD both should because it has so many lanes on the CPU) so a bad slot could theoretically trip up the CPU. If the CPU is freaking out it can freeze at random places in POST, but getting DRAM lights with a CPU issue is not uncommon. 

 

And just to be clear, parts of this is quite theoretical, I haven't seen a bad NVMe or M.2 slot cause DRAM debug lights before. As you have an iGPU I would do all the testing without the GPU so you don't have to reinstall it a million times, just to save on time. 

[LakelandHokie]

Looks like it was (I think) the ssd.  I was able to test it externally and was getting some errors, and then since getting a new ssd (Samsung 980 Pro 2TB) in the same M.2 slot that was causing issues before, everything has been golden.

[FoxTech83]

Had the same issue with crucial T500 2tb on an Aorus Master Z390. PC would not POST with C4 code on the MB and red light for DRAM. I have tried two different T500 2tb and in all M2 slots ( M2A, M2M, M2P) without any SATA or any device connected (even GPU). I tried the Lexar NM710 and the Intel SSD6 and it works on all the 3 slots without any issue. 

The only way I was able to make it run is by keeping only 2 bars of RAM (it detected only 1 while the crucial was installed). 

When I was able to POST only with 8gb out of 32gb I was able to use the Crucial. (btw I also bought new RAM to isolate the problem)

My conclusion is that the Crucial T500 is not compatible with the Aorus Master Z390 to my humble opinion. 

I guess the POST is trying to validate the DRAM on the M2 drive (shot in the dark as conclusion) but the other two M2 NVME are DRAM-less and my guess that is why it is not causing any issue!!?? I will have to try another DRAM SSD M2 drive to confirm anyway. 

With Z390 it is Gen 3 and I can't take advantage of the speed (3500mb/s max on Gen3).

I haven't seen any similar case on the forums around so I give up my troubleshooting :).