Before pressing the power button, the Power Management IC (PMIC) must generate the stand-by voltages. : +3VALW and +5ALW
You can find the full schematic and boardview files through the following technical repositories:
The is a motherboard schematic specifically for the HP 15-bs series laptops, such as the HP 15-bs526ur . Developed by Compal Electronics (code-named CSL50/CSL52 ), this board is often a subject of "repair stories" in the tech community because it represents a common challenge in budget laptop engineering. The "No Display" Mystery
Charging LED is off; no voltage on the 3.3V/5V coils. La-e791p Rev 2.0 Schematic Diagram
The most frequent story surrounding this schematic involves the laptop powering on but showing . Technicians often use the Rev 2.0 schematic to trace a specific signal failure: EC_RSMRST# . This signal is a critical "handshake" between the Embedded Controller (EC) and the Southbridge; if it doesn't trigger, the CPU never wakes up, leaving the user with a glowing power button but a black screen. Common Repair Themes
Look for liquid damage around the LVDS (screen) connector, which often shorts the backlight high-voltage rail to data lines. Conclusion
Be careful when downloading .pdf or .dz (BoardView) files from forums. Always scan files with an antivirus before opening. Before pressing the power button, the Power Management
The LA-E791P relies heavily on the communication between the BIOS chip and the KB9022Q. If you have voltages but no boot, the schematic helps you verify the SPI bus signals (CS, CLK, Data) to ensure the firmware is being read. 4. Professional Repair Tips
The LA-E791P Rev 2.0 is a compact and highly integrated laptop motherboard designed for several popular HP models. It is the main PCB (Printed Circuit Board) for these computers, routing all power and data between the processor, memory, storage, and peripherals.
Almost every schematic starts with a Block Diagram. The "No Display" Mystery Charging LED is off;
The falls under a well-known naming convention used by original design manufacturers (ODMs) such as Compal or Quanta . The "Rev 2.0" designation is crucial: it indicates a major iteration from the initial Rev 1.0.
Are you currently troubleshooting a or a display problem with this specific board? CSL50 LA-E791P Rev 2.0 Schematic | PDF - Scribd
