I’m seeking help with a modded BIOS for the ASUS Prime Z390-A motherboard to properly support an Intel CC150 CPU (OEM, similar to i9-9900 but locked). Here’s my situation:
Issue:
The CC150 (CPUID 906E0) worked on BIOS v2004, but newer BIOS versions (e.g., 2101) fail to boot (red CPU LED).
Downgrading to v2004 no longer works (ASUS seems to have altered the microcode in re-releases).
Request:
Could someone provide or create a modded BIOS with:
Microcode for 906E0/906EC (to bypass ASUS’s OEM checks).
Hi, I’m experiencing the same issue with the CC150 on the ASUS Prime Z390-A.
Whenever the system follows the BIOS Fast Boot path, the motherboard shows a red CPU LED, the screen stays black, and the machine completely hangs — I can’t even enter the BIOS.
However, if I clear the CMOS or disconnect power, then on the next boot the board goes into Safe Boot mode instead of Fast Boot, and in that case it starts up successfully.
But as soon as I reboot, it falls back into the endless loop again (red CPU LED → black screen → hang).
It really seems related to how the BIOS handles microcode initialization for the CC150.
Thank you for your input. While I agree that a damaged CPU is theoretically possible, the evidence suggests this is almost certainly a BIOS-level compatibility issue, not hardware failure. Here’s why:
1. Prior Functional State
The CC150 worked flawlessly on BIOS v2004 .
Issues began immediately after updating to BIOS 2101 (and persist even when reverting to newer “v2004” files from ASUS).
If the CPU were damaged, it would have failed suddenly during operation—not after a routine BIOS update.
2. ASUS’s History with OEM CPU Restrictions
Multiple users report similar issues with OEM CPUs (e.g., Xeon E-2100/CC150) on ASUS Z390 boards after BIOS updates:
Reddit threads
Win-Raid cases.
ASUS has silently added OEM checks in newer BIOS versions (e.g., blocking non-retail CPUs).
No matter which official ASUS BIOS I flash now (v2004, 2101, or older) – via SPI programmer or USB – the CPU fails to boot. All versions after the original v2004 (which worked) seem to block the CC150. I need a modded BIOS with the original microcode or patched checks.
Unfortunately, I never saved the original v2004 BIOS file that worked with my CC150. All official BIOS downloads from ASUS (including the re-uploaded v2004) now seem to have altered microcode that blocks this CPU.
If anyone has a backup of the original v2004 BIOS (before ASUS changed the microcode) and is able to upload the file, please share a download link. I can flash it via SPI programmer (CH341A).
Tested the CC150 on a different board (ASUS TUF B360-PLUS Gaming) to confirm the CPU was working.
Ruled out hardware faults on the Z390-A by testing with a known-good CPU (Pentium G5420). The same red CPU LED error persisted, even with the good CPU.
Performed a BIOS downgrade on the Z390-A to version 1905 using the G5420. This allowed the system to boot normally.
Updated the BIOS to the latest version (v2101) with the G5420 still installed, using ASUS EZ Flash.
Reinstalled the CC150. The system booted successfully with BIOS v2101.
Conclusion: The solution was to use a supported CPU to downgrade and then re-upgrade the BIOS, which somehow reset the microcode or compatibility checks. No BIOS modding or programmer was needed. This empirical method worked where a simple CMOS reset or reflash failed.
That’s a really detailed explanation of your issue, and it definitely helps others understand what you’ve already tried. It sounds like the microcode changes in the newer BIOS are the main blocker here. Hopefully someone with experience in modding ASUS BIOS files can step in and share a working build or at least guide you through patching the microcode properly. This is a tricky one, but your post lays out the situation clearly.