BIOS archive for the Dell Inspiron 15 3521, described in the name as tested and working. The 3.07 MB RAR has no board number or chip size listed, so open it to see the image size and compare it with the flash chip fitted on the board. A technician uses such a dump to recover a laptop with corrupted firmware by writing it with an SPI programmer. Save a backup of the original first, since it holds the service tag and other system-specific data.
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 @laptexdna. 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 →