Archived firmware for the S551LA, about 3.21 MB in ZIP form, identified only by model code. With no version or board number in the name, open the archive and verify that it holds a full flash image or a capsule update before choosing a method. The LA variant uses integrated graphics, unlike the LB and LN siblings, so use the file only on the matching configuration. When programming the SPI flash directly, read and store the existing content first and check that the image fits the chip.
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 @biosbigarchives. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →