Asus Maximus Z790 board experiencing Q-Code 16 error during startup
Asus Maximus Z790 board experiencing Q-Code 16 error during startup
My configuration: CPU model Core i9-13900K, motherboard Asus ROG Maximus X790 Extreme, RAM Kingston Fury Renegade 6400MHz CL32 (2 x 16GB), graphics Asus ROG Strix RTX 4090 High. I’m encountering a recurring Q-Code Error 16, which shows the small screen prompting “Check CPU.” In the manual this relates to version 15-18 and mentions “Pre-memory System Agent initialization started.” I’ve re-seated the CPU, tried using only one RAM stick per slot, rearranged both in the second and fourth slots, replaced the 24-pin connector, and even switched to the official BIOS. The issue persists after updating to BIOS 0701, but still won’t boot Windows smoothly. I can launch Windows directly after a restart without the error, yet it appears to appear only during shutdowns or restarts. The problem seems tied to power interruptions—after a shutdown or restart, the PC fails to boot properly. I suspect a power-related fault with the new hardware, drivers, or a failed reinstall. A recent Nvidia driver update caused a restart that cut power, leading to a corrupted installation and the Code 16 error. I resolved it in Safe Mode with DDU, but now reinstalling drivers is hindered by the motherboard’s error. I’m currently using the system under Derbauer’s 70W power plan, running games as a stress test and normal operation without issues. The trouble arises only during restarts or power interruptions. Some users on Reddit have shared similar experiences with this model. Any advice would be greatly appreciated. Thanks!
MRC Fast Boot and MCH Full Check are likely in the RAM configuration options.
Thank you for the feedback. I tested all four settings and none resolved the issue.
I don't see a setting named "Maximus Tweak" in the RAM settings. It might be a custom or less common option, so you may need to check your specific device documentation or contact support for more details.
This matter seems resolved. I finally assembled all the components to begin constructing The Beast. The Check CPU Error / Code 16 appeared exclusively during a warm or soft reboot—not during a cold or hard restart. I assumed ASUS would respond, noting it wasn’t related to the motherboard or any other ASUS product. My reply to another ASUS message: Have you tried similar solutions? Motherboard model: Asus ROG Maximus Z790 Extreme, Serial No. R1MCKC00... The problem was that the Check CPU Error / Code 16 showed only after a warm or soft reboot. First incident: I followed the initial boot steps to fix it. Solution steps included: keeping only the CPU stick in memory on DIMM_A2, disabling BIOS settings by removing the CMOS battery, waiting five minutes before reinserting it, then reinstalling the BIOS with default options. I cleared all partitions, reformatted the M.2_2 SSD, removed M.2_3 and DIMM.2 slots, cleared the Intel ARC 770 in PCIEX16/G5 slots, unplugged all non-essential devices from non-critical ports (USB, temp, fan, AAFP, SATA). I also have all the documentation and videos included in my message, but they never opened on Google Share. Thank you for reaching ASUS Product Support. My name is Sanique L., and I’m here to help! Please note that after working with the support team, it was confirmed it was a CPU error. Please troubleshoot: verify proper CPU installation, consult the manual for CPU setup or refer to the provided diagram. Take off the CPU, inspect for burn marks or dirt on the bottom using an eraser, clean gently. If no debris, check for bent pins in the socket—send the motherboard if needed. Run the IPDT Intel Processor Diagnostic Tool, download it, and follow instructions. If it fails, contact Intel for warranty replacement based on the diagnostic results. I previously ran the Intel Stree Test and included it in my submission, though I didn’t review it. I scheduled the Extreme Baby Brother for the next morning; it worked perfectly afterward—rebooted easily, exited sleep smoothly, and everything functioned correctly. 100% the motherboard is faulty now. I’m concerned about ASUS, especially since Linus is worried and I’ve already spent $27.31 on shipping. Delivery is set for tomorrow, 6/6/2026. It’s not a big deal, but I need multiple monitors to track code updates and testing in real time.