Firmware image for the Dell OptiPlex 3090 Tower desktop, marked tested by FST FIX. The name lists no motherboard number or revision, so compare the board markings on your unit before using it. The 10.6 MB RAR archive likely holds a full flash dump for writing straight to the SPI chip with a programmer such as a CH341A, used to restore a board that powers on without display. Keep a backup of the existing chip, and check the image length against the chip capacity.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @generalbios. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →