ASUS Bios Flashback specifications detailed questions
ASUS Bios Flashback specifications detailed questions
Hey everyone, just checking in—no POST issues. The computer ran perfectly until I powered it down and restarted it. When I came back on, there was no display and the CPU light was lit. I lowered the voltage and tested with Prime95 a couple of months ago without any problems. It seems the problem might be linked to the voltage adjustment. I tried using the BIOS flashback tool on the ASUS board, but it didn’t work. The flash drive appears to read correctly, then the light stays on for over 30 minutes before nothing happens. The motherboard is an ASUS Sabertooth 990FX R2.0 and the CPU is an AMD 8350. Any tips or missing steps for proper BIOS flashback execution? Thanks!
To fix an undervolt issue causing no-boot, you don’t have to re-flash your BIOS. Simply reset the CMOS by taking the battery out or connecting the correct pins. If you still wish to use BIOS flashback, rename the file to "ST990R20.CAP" Spoiler
Additional insights from @Kid.Lazer highlight common mistakes. The instructions specify saving the file directly to the USB storage root directory. Downloading the BIOS, extracting it, and placing only the renamed file onto the drive works best. Avoid adding it inside a folder. Ensure the USB is formatted correctly—FAT32 is recommended—and there have been no issues encountered so far. The renaming process can be done via the Renamer tool or simply by right-clicking and renaming.
Attempted startup using a dead battery and CMOS reset pins; system failed to power on despite red CPU indicator.
Power from the wall to the PSU was either cut or the PSU cable was disconnected. If you either remove the CMOS battery or reset the BIOS pin, and the PSU remains active, it won't reset the BIOS. The PSU supplies steady backup power to the motherboard as long as it stays plugged in and the switch is turned on.
That would reset the CMOS. Reducing CPU voltage won't destroy it—excessive voltage through overvolting is what causes damage. Which BIOS version are you trying to update? The newest one (such as 2901)? How much storage does your USB drive hold, in gigabytes? Is it USB 3.0 or USB 2.0?
I understand. You must change the name first, or the USB BIOS won't recognize it. If you were navigating through BIOS to update firmware, you likely don’t need to rename it. Get the file, find it in the compressed folder, and unzip it. You’ll have a .CAP BIOS file. Following the Sabertooth 990FX R2.0 manual, rename it to ST990R20.CAP. After that, power down the computer while keeping the motherboard powered. The PSU is connected, the switch is on, and the CMOS battery is restored—jumper remains off for reset. The ATX 24-pin connector should be connected to the motherboard’s USB port. Press the USB BIOS Flashback button.