The EC handles power sequencing. In the schematic, you will see the "Power Button" matrix.
Measure the voltage on the current sensing resistor (usually labeled R010 or similar near the charging area). If it reads 0V, trace back to the entry MOSFETs.
Connects the CPU directly to the RAM slots. La-e791p Rev 2.0 Schematic Diagram
: Firmware downloads for various HP 15-bs variants are available at Video Walkthroughs
Usually located in the first few pages, this table provides an absolute reference of what resistance values and voltage readings you should expect across every operational mode (S0, S3, S5). Conclusion The EC handles power sequencing
Look for the Charging IC (e.g., BQ247xx series).
Typically an ENE KB9022Q or similar chip responsible for power sequencing, keyboard scanning, and thermal management. Decoding the LA-E791P Block Diagram If it reads 0V, trace back to the entry MOSFETs
CPU core and graphics core power rails managed by complex multi-phase PWM controllers. 3. Core Power Sequencing and Troubleshooting Stages