Question Why x570 system not starting with 2 DRAM modules?

[zionkv]

Hello, everyone!

My build:
CPU: Ryzen 5900X
MB: MEG-X570-UNIFY
RAM: G.Skill F4-3600C18D-64GTRS
PSU: Corsair AX1600i
Video: 2 x ZOTAC RXT 3090

The problem:
If I put 2,3,4x DDR modules - the system wouldn't start.
XMP or not - DDR speed always 2666 instead of 3600 and DDR voltage is 1.220V instead of 1.4V.
I tried XMP1 and XMP2 - same. I tried to overclock, overvoltage memory - not helping. All memory banks is ok, checked with another PC and one by one.
Error codes is different, sometimes it's 0d.

CPU<->MB<->RAM = all in QVL

Is it broken motherboard?

 

[Colif]

SO you tried slots A2 & B2? (slots 2 & 4 from cpu)
as thats what you meant to use for 2 sticks
see page 5 - https://download.msi.com/archive/mnu_exe/mb/E7C35v2.2.pdf

 

[zionkv]

SO you tried slots A2 & B2? (slots 2 & 4 from cpu)
as thats what you meant to use for 2 sticks
see page 5 - https://download.msi.com/archive/mnu_exe/mb/E7C35v2.2.pdf

2&4 slots is most problematic. Even if I put single module in 2 or 4 slot - it would not start 70%.

Now it starting only when DRAM in slot 1.