Topic 6 of a Spanish smartphone repair course, focused on diagnosing and solving hardware faults, in a 308 KB PDF. No model or board number is stated. Such lessons usually explain checking current draw on a bench power supply, locating shorts, testing charging and power circuits, and inspecting for liquid damage or broken components. For actual board work it should be paired with the schematic and boardview of the specific device, since generic advice cannot replace exact rail names and test points.
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 @canalesquematicos. 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.