So I was able to fix my unit in the end, and for anyone stumbling across this with a similar issue - the service tag is not stored in the BIOS region. I have no idea where it hides, probably encrypted in one of the other parts of the UEFI? It also seems that 10th-gen Intel processors are more prone to just being stubborn about not saving the service tag when flashed with another BIOS from what I read online? Anyway. Also, it seems important to work with the same version BIOS when transplanting volumes around. In my case, I had the very first version released for the OptiPlex 7080 and was attempting...

Hello,

I have a Dell OptiPlex 7080 Micro with a suspected corrupt BIOS. Symptoms are no POST - 3 amber 6 white lights: SBIOS Flash corruption. I have a backup taken with a CH341a. I have flashed a known working BIOS onto the machine and that fixed it - but the computer is stuck in manufacturing mode and will not save the service tag, error code 8AC6D992.

Is there anyone knowledgeable who could take a look at my bricked BIOS, or alternatively add my service tag to the working BIOS to get it out of manufacturing mode? I am learning as I go but without being able to compare...

Hello!

Long time IT nerd, now finally trying my hand at BIOS repair!