
So I reseated the CPU and I tried the same operation written above, same results even without the heatsink (DIMM_B2 boots, DIMM_A2 don't), so I think we can exclude the heatsink/socket problem. So I decided to remove the heatsink and check the socket: all the pins are straight and evenly spaced. I repeated the whole operation with the other RAM stick, but I had the same result. Turned on the PC and it gave the 55 error code. So I shut down the pc again, removed the RAM stick and placed it into the DIMM_A2 slot. It went past the POST and booted into Win10. Then I put a RAM stick in the DIMM_B2 slot and I booted my pc. I cleared the CMOS pressing the button, in order to have a "clean" environment. I shut down my pc, unplugged everything except keyboard, mouse and HDMI monitor. I've just tried everything you suggested. If they won't work in the 2 RED slots, try 1 stick in 1 RED slot, then try the same stick in the 2nd RED slot, then try the other stick in each slot to determine if you have a bad memory module or possibly slot but more likely it's a memory module or you need to remove CPU check for damaged socket pins and carefully re install the CPU and heatsink being careful to cross tighten the heatsink and not over tighten, then repeat above steps


They are under performing because they are running in single channel mode. If you are using a 2 stick kit they need to be placed in the RED slots for dual channel.
