Question A1 A2 Dimm Slots on ASUS Z370

[Kalz2603]

Hi,

I have 2 x 8GB DDR4 ram on an ASUS Z370-A II motherboard.
I recently started getting random BSODs. The RAM was originally in B2 A2 as per mobo manual and has been working fine previously.
I know the ram is ok as I have done memtest86 and also tried new ram.

problem is:
if I use any of the A slots my system won’t post but will go into safe post after a few power on off cycles.
however, if I use B1 A1 and if I do the MemOk test using the button on the motherboard the system boots with
“memory ok! System succeeds in booting..”
however when I go to bios as advised to save settings. it then doesn’t post.

if i use B1 B2 all is working fine.

 

[punkncat]

Did you possibly remove the CPU, perhaps accidentally, while changing a cooler or repasting just before this issue presented?

This could be a variety of things. Assuming just two sticks of matched RAM here, but if the above is true you should check the LGA grid on the mobo to make sure you didn't accidentally bend some pins. Could be an issue with the memory controller on the CPU. Could be the motherboard.

Are you using any overclock including XMP?

 

[Kalz2603]

Hey.

nope - not removed the cpu. I did a while back change cases but the BSODs only started recently. might be worth removing the cooler and inspecting the pins.

regarding CPU - when able to get into windows (ram in B1 B2)
intel processor diagnostic tool shows Pass
prime95 runs fine on blend tests

and also not currently using XMP or overclocked CPU

 

[punkncat]

If you aren't using XMP that rather suggests that the issue with the RAM isn't VRM related. This motherboard isn't old enough that I would think this to be true...but do you have a fiberglass pen or some deoxit? (I probably spelled that wrong)
Might be worthwhile to clean the connectors on the ram and the motherboard to see if that changes anything.