I'm troubleshooting an ASUS ROG STRIX Z370-G Gaming (Wi-Fi AC) with an Intel Core i5-8400 and two Kingston HyperX Fury 8GB DDR4-3200 modules. Either stick boots normally by itself in both A2 and B2, but installing both modules causes one long beep followed by two short beeps repeatedly, an orange DRAM LED, and no POST. I've also tried both modules in A1 and B1, reseated them several times, and removed and reinstalled the battery to reset the CMOS. What should I test next, and what could make both modules work separately but fail when installed together?
2 Answers
Since each stick and each slot works on its own, the issue may be memory training, BIOS settings, or the CPU’s memory controller rather than a completely dead module. Start with a proper CMOS reset, then boot with both sticks installed at default settings. Make sure XMP is disabled initially; DDR4-3200 may need to be configured after the system successfully trains the memory. If it still fails, update the motherboard BIOS and check that the kit is installed in the recommended paired slots, normally A2 and B2.
Run MemTest86 with one module at a time, using the same slot and default BIOS settings, and let several passes complete. A module can boot Windows alone but still fail memory tests or become unstable when both are used. If both sticks pass separately but fail together at stock settings, inspect the CPU socket for bent pins, reseat the CPU and cooler evenly, and check for BIOS compatibility or a problem with the processor’s integrated memory controller. Also confirm the two modules are a matched kit; mixing separate kits can cause dual-channel training failures even when their specifications look identical.
I tried the recommended A1 and B1 combination as well, but both modules still produce the same DRAM light and beep pattern. I haven’t used MemTest86 before, so I’m also unsure how to check whether a stick can be faulty even though it boots by itself.