Help troubleshooting BSODs and failed POST

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17 Feb 2021
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Hey all,

Posted before about my watercooled build and this issue is for the same build.

CPU: Ryzen 5 3600 @stock with EKWB velocity block
MB: Asus Prime B450m-a
RAM: Corsair 2* 8gb (CMK16GX4M2Z3200C16) @ 3200mhz 16-18-18-36 1.35v in DIMM_A1 and DIMM_B1 - edit: these are the new modules I installed 4 weeks ago.
Added in Corsair 2*8gb (CM4X8GD3200C16K4) same as above, but reported in MB as 2133mhz and in DIMM_A2 and DIMM_B2 - edit: these are the old modules
GPU: MSI Mech OC RX 5700XT with Bykski A-SP5700XT-X block
PSU: Corsair RM750X
Pump/res: Corsair XD5 RGB
Rads: 1*alphacool 240mm 1*EKWB 360mm

Issue 1:
Booted PC this AM after no issues last night
BSODs repeatedly: 0xc0000221 and 0xc0000428
Troubleshooted with USB boot media
Startup repair didn't work
Regular Youtube fixes for above issues didn't work
Fresh install - still had BSODs
Removed old RAM - the second listed set
BSODs went away
Installed all my drivers, multiple restarts, no issues
Ran Guild Wars 2 which is my main - no issues
?faulty RAM
Left those sticks out, planned to test on their own until issue 2 occurred

Issue 2:
Went to BIOS to make sure fans don't boot up loudly
Realised I can't do this in BIOS because it's actually on Commander Pro
Now fails to POST ??didn't change any settings
Multiple attempts to reset defaults in BIOS, no bueno
Turned off D.O.C.P on a whim that RAM is faulty
Boots in just fine on auto mode

So - is the new AND old RAM at fault or could it be the motherboard?
Unfortunately I couldn't get the exact same model numbers and rather than buy a new set I added in 2*8gb. As you can see, they do vary in their model numbers.

I'd be really grateful for any tips on how to troubleshoot this properly or if I've missed anything. I've never troubleshooted faulty RAM or motherboards.

Kind regards,
Matt

Edit: Build has been perfectly stable for the past year, with D.O.C.P on the old RAM. Stress tested for many hours under Prime95.
 
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Brief update:

Using the old NEW memory modules
-Still won't post with D.O.C.P @ 3200 (it's done this successfully for the past year)
-Managed to pass POST with D.O.C.P @ 3000
-Currently stressing with Prime95

Not sure on next steps... Maybe ensure chipset drivers are up to date. Maybe flash BIOS.

Edit: POST successfully with old modules in A2 + B2 @ 3200 mhz. Only runs @ 3000mhz in A1 + B1.

Edit 2: I got the model numbers the wrong way round. The CM4X8G set is the OLD set. These are the ones when removed allowed me to have no BSODs and POST fine. Will trial them on their own.
 
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I'm now thoroughly confused. This is the exact same arrangement as before when I had BSODs and failed POSTs. Running in BIOS at DOCP 3200 @1.35v.
As above - all I did was remove A2 and B2 (per below screenshot which is current) which then prevented the BSODs.
I then was unable to POST at 3200 with A1+B1 as below, but could with the same modules in A2+B2.
I then tested the current A2+B2 as below at 3200 and it was fine.
Threw in the current A1+B1 and also no issues at 3200 DOCP.

Hoping someone can shed some light on this because of course I don't want it to happen again. Checked the QVL and my models aren't in it for the MB.

DQ9NDRS.png


IZNFjaN.png


Slot 1+2:
DbYbl89.png


Slot 3+4:
oic6cP6.png
 
When having different DIMMs it can be picky in which slots they have to be.
Because of very possible use of different DRAM chips, in theory compatible DIMMs can be not so compatible in practise:
If BIOS uses chips capable to faster performance as reference for setting values, chips in other DIMM might not be able to keep up.
So having DIMMs in different order can stabilize things in certain cases.


Also you should have some good airflow over motherboard.
That VRM is garbage good for only 65W TDP CPUs when having heatsinks...
And without heatsinks it's more like VRM for 45W TDP CPU.
 
When having different DIMMs it can be picky in which slots they have to be.
Because of very possible use of different DRAM chips, in theory compatible DIMMs can be not so compatible in practise:
If BIOS uses chips capable to faster performance as reference for setting values, chips in other DIMM might not be able to keep up.
So having DIMMs in different order can stabilize things in certain cases.


Also you should have some good airflow over motherboard.
That VRM is garbage good for only 65W TDP CPUs when having heatsinks...
And without heatsinks it's more like VRM for 45W TDP CPU.

Appreciate the tips - I was certain the DIMMs were bricked. I'm still not fully unconvinced of that.

Thanks for the info re the MB. It came in a pre-built when I wasn't physically able to build myself, will consider for the future re upgrading.
 
BSODs returned with a vengeance. Removed and left out the old modules for now. Running on DOCP at 3200 with the new modules, currently is passing memtest86 and will leave running all morning. Will just assume this motherboard can’t handle the slight difference in DIMM model numbers and call this solved I think.

It was a nice idea to have 32gb, but I’ll do it properly next time!
 
The manual of your board says that 2 dimms (only) are supposed to be in a2 and b2.

Usually XMP speeds, timings and voltage is only rated for 2 sticks with 2 stick kits (even in the QVL).

From what I recall, for Zen 2, 4 single sided is only rated officially up to 2933.

What I'd try is running all sticks at 2666, dram voltage 1.2v, board defaults for timings. If that works then try stepping up to 2933, dram voltage 1.35v, board defaults for timings.

You could also try a higher voltage at 3200, like 1.4v.
 
The manual of your board says that 2 dimms (only) are supposed to be in a2 and b2.

Usually XMP speeds, timings and voltage is only rated for 2 sticks with 2 stick kits (even in the QVL).

From what I recall, for Zen 2, 4 single sided is only rated officially up to 2933.

What I'd try is running all sticks at 2666, dram voltage 1.2v, board defaults for timings. If that works then try stepping up to 2933, dram voltage 1.35v, board defaults for timings.

You could also try a higher voltage at 3200, like 1.4v.

Thank you, posting just fine at 2800mhz :)
 
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