My wife's newly built PC has failed to start normally since its very first boot. The system uses an ASUS TUF Gaming X870-PRO WIFI7 W NEO motherboard, Ryzen 7 9800X3D processor, 32GB Corsair Vengeance DDR5-6000 memory, Samsung 990 PRO 2TB PCIe 4.0 NVMe SSD, and an ASUS Prime GeForce RTX 5070 Ti 12GB graphics card.
Whenever the PC is completely powered off, the motherboard shows a solid yellow-green diagnostic light on the next startup. The monitor detects an attempted signal but remains black, and the system does not POST. Clearing the CMOS and changing BIOS settings allows it to boot again, but the problem returns after the next full power-off. The BIOS changes are being saved correctly, and replacing the CMOS battery did not help.
Is this a known motherboard or BIOS issue? What could cause the yellow-green light and what would be a permanent fix?
2 Answers
Make sure the monitor is connected to the RTX 5070 Ti rather than the motherboard’s video outputs, and reseat the graphics card and memory. It would also be worth testing with one RAM module at a time and checking whether the latest BIOS specifically improves Ryzen 9000-series memory training. If an updated BIOS, reseated hardware, and a known-good boot drive do not change the behavior, the motherboard may be defective and should be tested or replaced under warranty.
On this board, the yellow-green Q-LED corresponds to the boot-device check. That points more toward the motherboard failing to initialize or find the boot drive than directly identifying a graphics-card problem. I’d first check the manual’s exact Q-LED meaning, update the motherboard to the latest stable BIOS, and confirm that the 990 PRO is firmly installed in the recommended M.2 slot. Also verify that the saved BIOS profile is actually retained after a normal restart and after a complete shutdown.
The BIOS settings are definitely being saved, but after a full shutdown the system still sometimes refuses to POST. Clearing the CMOS is currently the only reliable way to get it working again.
The system is using the RTX 5070 Ti, and the CMOS reset is needed on every troublesome boot. I’m going to check the BIOS version and reseat the memory, GPU, and SSD before considering a board replacement.