Toshiba Satellite L30 repair archive in RAR format, roughly 2 MB, labelled with the code BL1. The name does not identify the board maker or the files inside; BL1 is likely a project code, so compare it against the markings on the motherboard. Schematic sets like this are used to follow the power sequence, test the voltage regulators and charger circuit, and track down shorted capacitors or MOSFETs. Extract it and confirm the title block details before relying on any reference designators.
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 @alischematics. 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.