System booth with 1 DDR5 in B2, but not A2/B2

Hi !

I got a brand new B650M PRO RS WIFI with AMD 7900X5D and two sticks of DDR5 6000.

When I plug only one RAM in B2 slot, the system boots.
When I plug both my RAM in the expected A2+B2 slots, the system doesn't boot (black screen) and two of the POST RED LED are on : CPU & RAM.
Each RAM stick work individually in B2.
I also tried to upgrade the BIOS with the USB flash to latest (v2.10).

What are the possible causes? My guess is either

- CPU is broken (memory controller?)
- Motherboard is broken

Is there any other possibility? Also what is the most likely?

Thanks!

Hi !

Yes I waited several minutes. I had read in the manual the hundreds of seconds to wait depending on memory size. I have 16GB. Although the manual should be improved. They should write what to expect during this waiting time (a black screen or ?). I will try the memory training options (not sure what the default of "Automatic" means), I wasn't aware of this option, thanks!

Memory part number: FF3D532G6000HC30DC01
Memory part name: Team T-Force Delta RGB 32GB (2 x 16GB) 288-Pin PC RAM DDR5 6000

Note that I found that if I put the two sticks in B1 & B2, it boots. But the system is unstable though. It crashed twice in this configuration. I'm back to running the system in B2 only

I ordered a new CPU and new motherboard. Still curious what are the possible cause in order or probability. Could it be the memory? I read that someone had same problem and swapped to an ASUS mobo and things worked flawlessly.

Thanks,
Francois