Hi there, It's possible that there is a motherboard fault causing this issue - one way to check this would be to test all your memory by installing it one stick at a time in slot DIMM1_A and seeing if the issue reoccurs. After this, try installing the memory, again one stick at a time in slot DIMM1_B. If you get the same issue occuring when the memory is installed in slot DIMM1_B, it would appear that this slot is faulty.
I have Dell PowerEdge 850 that my company bought 2nd hand few years ago. This server do not have warranty with Dell anymore. This server running smoothly before until early of this week the indicator light  start to blinking with red light (before this blue). I run Diagnostic boot from cd to check the problem, then it come out with "correctable ECC error,DIMM1_B" etc that i search on google said the memory problem. I tried to swap the memory with other server that i believe the memory is in good condition but the red indicator light is still blinking. I dont have any idea anymore to fix the problem, that anyone have solution on this matter, kindly advise to me. Thanks in advance.
Dell PowerEdge 850