Some Ram Slots models aren't compatible with the latest CPUs.
Some Ram Slots models aren't compatible with the latest CPUs.
I replaced my old Dell with an i7 27oo from an i3 2100. The new PC came with two 2x2 DDR3 modules, both functioning well and still doing so in slots 2 and 4, regardless of whether the same or different set is placed there. However, inserting anything into slots 1 or 3 results in missing USB or video connections.
I took out the CMOS battery and it started up, I restarted and attempted to install a RAM stick in the first slot but it didn’t work.
Ensure the motherboard has been reset properly. Verify that all four slots function correctly after reinstalling the previous CPU. There might be a CPU with a malfunctioning second channel—consider using a different board. Also, test with an M.2 slot if available.
It was also mentioned that there wasn't another motherboard, and everything functions with the previous CPU.
The issue seems to be with the pads on the i7 2700 located underneath. You might notice some signs of wear, though it could be hard to see.