Question DIMMA1 and DIMMA2 not working - here's what I've tried

[mulholland]

Hi all, so this entire week I've been struggling to get my new PC build working. Here's the spec list:

MSI x470 mobo
AMD Ryzen 3900x
2x Corsair LPX 32gb 3200mhz C16 DDR4 DRAM (total of 32gb)
EVGA Geforce RTX 2080

So as the title suggests my issue is that the RAM sticks refuse to let the computer boot when inserted into either of the DIMMA slots. They only work in single-channel mode in DIMMB1 and DIMMB2. They both work separately in both slots alone. When I try to use, let's call it stick A, in DIMMA1, I get a CPU error LED. If I swap it out for stick B and put it in the same DIMMA1, I get a DRAM error. They produce the same errors when used alone in DIMMA2. And of course they don't work when inserted as recommended into DIMMA2 and DIMMB2.

Here's what I've tried so far:

• RMA'd the mobo: same issue
• Tried a different Ryzen CPU (2200): same issue
• Examined both CPUs for bent pins: All are straight. However, BOTH CPUs seem VERY slightly warped, but laid on a flat surface all pins make contact.
• Tried different heatsink
• Tried loosening heatsink
• Updated BIOS to latest version
• Examined DRAM slots for debris
• Bumped up DRAM voltage and changed speeds
• Ran memtest: both came back clean

Given that the issue persists across two different motherboards and CPUs I'm inclined to believe one of the following:

• DRAMs are either bad or incompatible with this CPU (they are verified compatible with the mobo)
• The heatsink that I originally put on was clamped down too tight and bent both CPUs out of shape

I have replacement DRAMs of the same model coming in the mail today but I'm hesitant to open them if the issue is that I fucked up the CPU. Does anyone have any other ideas or am I on the right track with my thinking? The system works fine after booting as long as the DRAMS are in the DIMMB slots.

 

[helpstar]

Which MSI x470 mobo model exactly are you using?
Which exact Corsair LPX 32gb model number is it?

Did you reset the mobo by jumper after installing the two RAMs into a2 and b2 (second and fourth slot from CPU)?

Which BIOS version is now displayed within the BIOS?

Is the motherbpard inside a case or breadboarded?

Which heat sinks did you try?

Which PSU are you using?

 

[mulholland]

Which MSI x470 mobo model exactly are you using?
Which exact Corsair LPX 32gb model number is it?

Did you reset the mobo by jumper after installing the two RAMs into a2 and b2 (second and fourth slot from CPU)?

Which BIOS version is now displayed within the BIOS?

Is the motherbpard inside a case or breadboarded?

Which heat sinks did you try?

Which PSU are you using?

Thanks for the reply. Last night I may have gotten a little impatient and decided to roll the dice and see if the spare Aorus x570 mobo I had lying around that I got as part of a bundle with my Ryzen would work. Everything works great now with the x570, so I'm thinking there was some kind of incompatibility somewhere, or I got two bad mobos in a row (seems less likely).

 

[helpstar]

most likely incompatibilty issue with the BIOS from MSI and the new 3900X