Dell PowerEdge R620 Memory Problem

Hello everyone,

I bought Dell PowerEdge R620 server (24 slot motherboard) on march this year, on which I installed ESXi server and configured VMs. It has 2 Intel Xeon E5-2667 v2 3.30GHz 8-Core CPUs and  8x32 gb PC3 14900 LRDIMMs (256 in total). It worked brilliantly.

But 2 days ago suddenly I lost access to it. When I got to it physically I found out there was server hardware failure (there was some kind of errors on screen, like windows blue screen when hardware fails). I restarted it and during startup memory error appeared and server can't see one memory slot (instead 256 gm it is now 224 gb, but working).

Error: Memory initialization warning detected.

"DDR3 Training Failure - FPT - read DqDqs DIMM B2

MEMBIST memory test failure DIMM b2

 

I thought one of 32 gb DIMM module was dead. So I interchanged  DIMM modules and put different module on this B2 slot. Same error. Looks like memory DIMMs are alive and it is the B2 slot that's failed.

Maybe someone had similar problem and knows the cause.

What may be the reason of this memory error?

Thanks in advance