My 13-year-old son is trying to build his first PC using an ASUS Z790 Gaming WiFi7 motherboard, but we're hitting a snag because it won't POST, there's no display, and we can't access the BIOS. The CPU pump/fan is operational—it's spinning and the lights are on—similarly, the GPU fans spin as well. The SSD shows a red blinking light, and the front panel LED flashes white.
We've reseated the memory (GSkill RGB 16GB x2) in the recommended DIMM slots (A2 and B2), and the lights come on when powered. We also reseated the CPU (Intel Core i9-12900K LGA1700), using an external frame for the CPU cooler (Arctic Liquid Freezer III 360 A-RGB). We've tightened and loosened the cooler screws to ensure a good connection.
The HDMI cable is plugged into the GPU, but we've also tested it by connecting it to the motherboard directly. The GPU (ASUS Dual GeForce RTX 4060 EVO OC Edition 8GB GDDR6 PCIe 4.0) is installed in the closest PCIe 5.0 slot, which should be compatible with 4.0, though we haven't tried the lower PCIe 4 slot yet.
For storage, we're using an M.2 SSD (SAMSUNG 990 PRO 1TB PCIe 4.0 with heatsink) in the M.2_1 slot. We have the 24-pin and 8-pin power supply connectors attached, but we were not provided with the optional 4-pin connector (MSI Mag A850GL). No SATA drives are installed. The case is an NZXT H6 Flow. I have a USB drive with the BIOS loaded from the ASUS site, but I'm not sure if that can be useful without getting past POST. I'm at a loss on what further troubleshooting steps I can take to get this working!
2 Answers
Check that all your connections are secure, particularly the power cables to the motherboard and components. It might also help to take out the RAM and boot with just one stick to see if that makes a difference. And don’t forget to try resetting the CMOS—turn off the power, remove the battery for a minute, then put it back and power on. It can sometimes clear up weird boot issues.
Have you checked if the CPU has an integrated GPU (IGPU)? If so, you could try connecting your monitor to the motherboard instead of the GPU to see if you get any output that way. Sometimes if the dedicated GPU isn't initializing properly, it might be worth testing the IGPU first—especially on a new build.
Yeah, it looks like the Intel Core i9-12900K does have an IGPU (Intel UHD 770), so that could definitely be worth a shot!
Also, if you can, move the RAM to different slots one at a time while you test. Sometimes a slot can be faulty, which might lead to troubleshooting headaches!