Texas Instruments datasheet for the TPS51123, a dual synchronous buck controller with integrated 5 V and 3.3 V LDOs, supplied as a 2.40 MB PDF. In laptops this type of chip usually produces the main 3V and 5V system rails, including the always-on supplies. The document explains each pin, the enable and power-good behaviour, current-limit setting and typical schematics. Use it to measure VIN, the LDO outputs and the enable lines when standby voltages are missing, before replacing the controller itself.
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 @ic_mosfet_pdf_datasheets. 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.