Archive for the Samsung Galaxy A21, model SM-A215U, which is the US-market variant. The RAR file is about 5.5 MB and its contents are not detailed in the name, though repair packs of this size usually contain schematic or board layout PDFs. Use them to locate components, follow power and signal lines, and identify test points when diagnosing charging or boot faults. Open with WinRAR or 7-Zip, and make sure the model code on the back label is the U version, as other regions may differ.
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 @esquemaseletricos. 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.