I just built my new PC using an x870e hero motherboard, a 9950x3d CPU, and a 5090 GPU, but I'm facing a major issue. When I try to start the system, it shows a 15 error code and then just shuts down completely. It doesn't loop; it just turns off without even getting to the BIOS. I've tried swapping RAM slots and using just one stick at a time, but the same problem occurs. The yellow light signals a RAM issue when I try putting them in the A1 or B1 slots, but that doesn't make much sense to me since it suggests that the motherboard detects a problem. Both RAM sticks are brand new, so it seems unlikely both are faulty. The CPU is also new, so that shouldn't be the problem either. I'm planning to drain the custom loop to check the CPU itself before spending another $250 on RAM, but I'm hoping someone might have had a similar issue or can suggest a fix.
2 Answers
You might want to try installing the RAM in the 2nd and 4th slots instead and then check the BIOS for a setting called Memory Context Restore. Enabling that can help your system perform its memory training properly.
Make sure your memory sticks are inserted in A2 and B2 slots. And yep, you'll need your system to complete the memory training process, but it seems like it’s shutting off before it's even able to start that.
I have Trident Z Neo 6000 CL28 32GB sticks, which aren’t listed on the QVL but should still work since they’re AMD EXPO sticks. I placed them in A2 and B2. The system totally shuts down, including all fans and RGB lights—nothing is left on.
I can’t even get to the BIOS yet; it keeps shutting down before I can reach that point!