Check the DC-in MOSFETs (usually located near the battery connector) for shorts if the laptop isn't charging.
This article provides a hypothetical but technically rigorous reconstruction of what that schematic would contain, based on common design patterns of that era, standard component datasets, and functional analysis of the CML (Communication Modulation Logic) architecture. mantis cml mb 18778-1 schematic
Ensure the power management IC is producing these voltages before checking the power button signal. Check the DC-in MOSFETs (usually located near the
For advanced board-level troubleshooting, three types of files are often used in conjunction: Mantis CML MB 18778-1 Boardview Dell Inspiron 5590 standard component datasets