The main system rail (19V or battery voltage) that feeds all other regulators.
laptops (e.g., HP 15-ba009dx, 15-ba055ur). While "Rev 1.0" is a standard early revision, many technical archives and repair resources commonly reference Key Content of the LA-D711P Schematic lad711p rev 10 schematic top
Essential for DDR4 memory and the PCH logic. The main system rail (19V or battery voltage)
Generated by the TPS51225R (or similar) controller. These must be present before the laptop can trigger the power-on sequence. lad711p rev 10 schematic top