The "Rev 2.0" designation is critical. Dell and Compal (the OEM manufacturer) released multiple revisions of this board. A schematic for Rev 1.0 may have different resistor values, missing test points, or altered power rails compared to Rev 2.0. Always ensure your schematic matches the revision printed directly on the PCB.
A standard LA-E801P Rev 2.0 schematic PDF is typically divided into 50–70 pages. Key sections to look for include:
[19V DC-In Adapter] ──> [+19V_VIN] ──> [+3VALW / +5VALW Buck Converter] │ ┌────────────────────────────────────────┴────────────────────────────────────────┐ ▼ (S5 State) ▼ (S3 State) [+3V_EC / Power Button Active] ──> [EC Triggers PM_PWRBTN# to SoC] ──> [SoC Releases SLP Signals] ──> [+1.2V DDR4 VRAM Rail] │ ▼ (S0 Full Power State) [+1.0V PCH] ──> [+VCC_CORE] ──> [+VCC_GT] The Primary Voltage Rails
The 19V rail enters through a DC jack and must clear two isolation MOSFETs. If the laptop has , locate the charging IC (typically an Intersil/Renesas ISL or Texas Instruments BQ series controller). Check the gate voltage of the input MOSFETs. If the controller detects a short circuit downstream, it keeps the gate voltage low, isolating the motherboard to prevent fire hazards. The RAM Power IC (PUM1) la-e801p rev 2.0 schematic
Input MOSFETs (usually dual N-channel MOSFETs configured as reverse-polarity and over-voltage protection), current sensing resistor ( PR302 or similar depending on exact schematic notations).
Check the input protection stage. Measure the resistance to ground on the main B+ rail directly after the current-sensing resistor. A low resistance reading (below 10 Ohms) indicates a short circuit, usually caused by a ceramic filtering capacitor or an upper-phase buck MOSFET breaking down into a short. Power LED Blinks, but No Boot
: Confirm the processor releases the DRAM Reset signal ( DRAMRST# ). Lack of a reset flag usually indicates a corruption in the firmware or a microscopic fracture under the BGA processor assembly. The "Rev 2
A: Use OpenBoardView (free, open source) or FlexBV (paid, professional). Do not use ancient DOS software.
LA-E801P (also referred to as CSL50, CSL52, or CKL50)
2.0 (Commonly documented as Rev 1.0, but Rev 2.0 shares significant architecture) Application: HP 15-BS Notebook series Power Architecture & Components Always ensure your schematic matches the revision printed
Without the schematic, repairing the LA-E801P is a guessing game. With it, it becomes a science. Here are the top three failures I see on the bench and how the diagram guides the fix:
The is a highly sought-after component diagram used by component-level repair technicians to diagnose, troubleshoot, and fix the Compal CSL50/CSL52 (or CKL50)
The schematic outlines several critical power states and rail addresses for troubleshooting: