: Pinouts for the detachable keyboard connector, M.2 SSD slots, and the display (eDP) interface. Common Uses for the Schematic
Since this board charges via USB-C, the PD Controller (often a TPS series chip) frequently fails. The schematic helps identify the CC1/CC2 lines and the 20V input rail.
Shorted input MOSFETs or ceramic decoupling capacitors clamping the rail to the ground. +3VALW and +5VALW (Always-On Rails)
The primary power rail generated from the AC adapter or the battery pack via the charging circuit.
[19V DC-IN] ──> [VIN (19V)] ──> [+3VALW / +5VALW] ──> [EC KB9022 Powers On] │ [CPU Core Rails] <── [RAM Power (+1.2V)] <── [Power Button Pressed (EC_ON)] │ [PLT_RST# Released] ──> [BIOS Code Execution] ──> [System POST / Video Out] la-e801p rev 2.0 schematic
Only use BIOS BIN files from trusted sources like the IndiaFix.in thread or long-standing community members on Lab-One Inside. Before installing, use software like ME Analyzer to verify the BIOS version and ensure it matches your specific HP board revision. A bad flash can permanently brick the motherboard.
), the EC assumes the laptop screen is closed and ignores the power button entirely.
The SoC releases the sleep state signals: SLP_S5# , SLP_S4# , and SLP_S3# . As these lines go high, they act as enables for the remaining voltage regulators on the motherboard ( +1.2V , +1.0V , and eventually +VCC_CORE ). Step 5: Power Good and Reset
Check the high-side MOSFETs connected to the phase coils. If a high-side MOSFET shorts out, it can bypass the regulator and shoot 19V directly into low-voltage components, which often destroys the CPU. : Pinouts for the detachable keyboard connector, M
Locate the "Power Block Diagram" page (usually page 2 or 3 of the Compal schematic). Follow the arrows to trace which voltage rail enables the next. For instance, if +3VALW is missing, check the inputs and enable pins of the 3V PWM regulator chip using the schematic pinout map.
The motherboard architecture relies on an integrated System-on-Chip (SoC) layout, where the CPU and Platform Controller Hub (PCH) are bundled into a single package. Because of this, standard structural protection circuits are critical to saving the expensive processor from power surges.
Symptom: Completely Dead Board (No Charging Light, No Power)
Look for the EN (Enable) signal for the missing rail. If the controller has power but no Enable signal, the issue lies further back in the logic sequence (often the EC or PCH). Conclusion Before installing, use software like ME Analyzer to
LA-E801P (also referred to as CSL50, CSL52, or CKL50)
If 19V is present but +3VALW is missing, check the 3V/5V standby IC. Feel if the IC is getting hot. A short circuit on the +3VALW line (often a dead EC or shorted PCH) will pull this rail to ground, causing the regulator to overheat.
Detailed descriptions for the keyboard connector, LCD/EDP connector, and battery interface. Where to Find the LA-E801P Rev 2.0 Schematic
If you are a laptop repair technician or an electronics enthusiast, coming across the is like finding the DNA of the laptop. Used primarily in Dell Latitude 5289 2-in-1 models, this Compal motherboard is a sophisticated piece of engineering that integrates power management, high-speed data, and display signals into a compact PCB.