Dell OptiPlex 5080 with no service mode jumper

I have a Dell OptiPlex 5080 with AMT enabled, but no KVM. I can’t find a service mode jumper anywhere on this motherboard to output a full SPI/BIOS image. “fptw64 -d spi.bin” gives an "Error 185: FCERR is set. Hardware sequencing failed. Make sure that you have access to target flash area."

If I try “fptw64 -d spi.bin -ME” than I have success, but it’s only 15348KB instead of the full 32768KB. Also, ME Analyzer says “FWUpdate Support: Impossible” for this spi.bin file.

Any suggestions?

[Guide] Unlock Intel Flash Descriptor Read/Write Access Permissions for SPI Servicing

Or GRUB/RU [GUIDE] Grub Fix Intel FPT Error 280 or 368 - BIOS Lock Asus/Other Mod BIOS Flash

The closest I got was your second link. I opened the spi.bin that I had saved via “fptw64 -d spi.bin -BIOS” with UEFITool.exe. I searched for “BIOS Lock” via Unicode text and only found one instance: "Unicode text “BIOS Lock” in “Setup/PE32 image section at header-offset 8DAAAh”. I extracted that section as-is to Section_PE32_image_Setup.sct and extracted it to a .txt file via Universal IFR Extractor7.exe. In the .txt file I searched for BIOS Lock and found this:

0x5C77A One Of: BIOS Lock, VarStoreInfo (VarOffset/VarName): 0x17, VarStore: 0x17, QuestionId: 0xD97, Size: 1, Min: 0x0, Max 0x1, Step: 0x0 {05 91 65 0B 66 0B 97 0D 17 00 17 00 10 10 00 01 00}
0x5C78B Default: DefaultId: 0x0, Value (8 bit): 0x1 {5B 06 00 00 00 01}
0x5C791 One Of Option: Disabled, Value (8 bit): 0x0 (default MFG) {09 07 04 00 20 00 00}
0x5C798 One Of Option: Enabled, Value (8 bit): 0x1 {09 07 03 00 00 00 01}

I renamed bootx64.efi to shell.efi and booted off it OK via a USB thumbdrive. In grub I typed “setup_var 0x17 0x0” and got an output similar to what the screenshots in the instructions expected. I rebooted into Windows but I still can’t run “fptw64 -d spi.bin” without the same Error 185 as before.

I booted into ru.efi (the third link), but that one was way over my head with little to no instructions.