I built a system with a B850 Aorus Elite WiFi 7 motherboard and a 32 GB Corsair Vengeance RGB kit containing two 16 GB sticks. The computer boots normally when either stick is installed by itself in the A2 slot, but installing the second stick in B2 causes the motherboard's red DRAM indicator to turn on and the system fails to POST. I've already given memory training plenty of time, updated the motherboard drivers, and tried changing BIOS settings, including EXPO. Both sticks work individually in A2, so the modules themselves appear to be functional. Removing the second stick sometimes leaves the system in a state where I have to reinstall the operating system and set everything up again. This is my first build, and I'm running out of troubleshooting ideas. What should I check to get both memory sticks working?
2 Answers
Double-check the slot labels printed directly on the motherboard rather than relying on what the BIOS calls them. Some BIOS screens label the physical slots differently, and the recommended pair may not be the two slots you expect. Also reseat both modules firmly, inspect the slots for debris, and make sure the CPU cooler isn’t applying excessive pressure. An improperly seated CPU or bent socket pin can interfere with one memory channel and produce a DRAM light. If the correct slots still fail with BIOS defaults, test with one stick in each slot; that can help distinguish a bad slot or memory channel from a configuration problem.
The CPU model and exact BIOS version are important here. Memory compatibility and dual-channel support depend heavily on the processor, and a BIOS update may be needed even if all of the motherboard’s normal drivers are current. BIOS firmware is separate from chipset and device drivers, so check the board’s support page for the newest stable BIOS and follow the update instructions carefully. Before testing, load BIOS defaults and leave EXPO disabled. Confirm that each stick works alone in A2, then test the pair in the recommended A2/B2 slots. If the system only fails with EXPO enabled, the memory profile may simply be unstable and may need a lower speed or manual settings.
I’ve seen systems report the physical third and fourth slots as A1 and A2 in the BIOS, so the labels shown there may not match the silkscreen on the board. I’d verify the manual’s installation diagram first, then update the BIOS rather than treating driver updates as firmware updates.