Electrical schematic for the LG K40S smartphone, delivered as a 13.0 MB PDF; the E.E prefix in the name likely refers to the electrical section of service documentation, but is not certain. Phone schematics like this let a technician follow the battery, charging and PMIC rails, locate test points, and trace display, camera or USB lines when diagnosing faults such as no power or no charging. Verify that your board matches the model variant, since component placement can differ between regional versions.
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 .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.