Two PCs using Ryzen 7 7700X processors started having the same problems after receiving Windows 11 updates. Both machines worked reliably for years beforehand. On a cold start, they often show the CPU and RAM diagnostic lights and fail to boot, but usually start successfully after 4–10 restart attempts. RAM has been reseated, swapped, and tested; CMOS has been reset; the CMOS batteries have been replaced; and PC2 was wiped and given a fresh Windows 11 installation with memory overclocking disabled.
PC1 uses an RTX 4080, an MSI X670E Carbon WiFi motherboard, 64GB of DDR5-5600 memory, and a 1000W power supply. PC2 uses an RX 9070 XT, an MSI B650 Carbon WiFi motherboard, 32GB of DDR5-6000 memory, and the same CPU and power-supply model.
PC1 also has a display problem with a Samsung Odyssey G55C 32-inch 1440p 165Hz monitor: the screen is blank during startup and only displays an image during automatic repair or once Windows reaches the desktop. That monitor works normally when connected to an older Intel-based PC. PC2's Samsung widescreen monitor works with both AMD systems, and the G55C also works with PC2 once connected. Could the Ryzen processors be responsible, or is this more likely a motherboard, BIOS, memory-training, graphics-output, or monitor-handshake issue? Is there anything practical to try before calling a repair technician?
2 Answers
The timing may point to the update, but the symptoms sound more like early-boot hardware initialization than a Windows installation problem. Since the CPU and RAM diagnostic LEDs appear before Windows loads, try updating both motherboards to their latest stable BIOS versions, then load BIOS defaults and leave memory overclocking disabled. Also check that the memory is installed in the recommended slots and allow a few minutes for DDR5 memory training after clearing CMOS. If the systems still need several power cycles, test with one known-good DIMM at a time and disconnect unnecessary drives and USB devices. A repair shop may be worthwhile if both boards continue failing at the same stage.
The monitor behavior may be a separate DisplayPort or HDMI handshake issue rather than evidence that the Ryzen CPUs are defective. Try a different certified cable, another output on the graphics card, and temporarily set the monitor to a lower refresh rate or disable FreeSync. Testing with the monitor powered on before starting the PC can also help. Because the monitor works with the Intel machine and another monitor works with both AMD PCs, the display and graphics-card firmware/output combination is more suspicious than the CPU itself.
The two AMD systems received the update at different times. The first began having the problem after a manual update, while the second showed the same behavior immediately after its update was forced. PC2 has already been wiped and reinstalled, but the cold-boot issue remains.