Welcome to the professional repair lab at geniusmind4u.blogspot.com. Today we are deep-diving into the ACER ASPIRE S5-371 and S5-371T series, powered by the Compal LA-D591P (B3ZMS) motherboard. This ultra-slim platform requires precise chip-level diagnostics. Whether you are dealing with a 'no power' scenario, liquid damage, or a BIOS failure, the following technical resources and schematic diagrams are essential for successful logic board restoration.
Motherboard Specifications
| Feature | Details |
|---|---|
| Laptop Brand & Model | Acer Aspire S5-371 / S5-371T |
| Motherboard Code | Compal LA-D591P B3ZMS Rev 2.0 |
| Platform Architecture | Intel Skylake/Kaby Lake-U (SOC) |
| EC / KBC Controller | ENE KB9022 Series |
| Primary Power Rails | VIN (+19V), +3VALW, +5VALW, +VCC_CORE |
Common Chip-Level Faults & Diagnostic Notes
- 19V DC-IN & Current Sense Resistor (PR301/VIN) Diagnosis: If the laptop is completely dead, check for 19V at the main current sense resistor (PR301). If voltage is missing, inspect the input MOSFETs (PQ301/PQ302) for shorts. A common failure point in the LA-D591P is a shorted ceramic capacitor on the B+ rail, which triggers the charger's OCP (Over Current Protection).
- 3.3V / 5V Standby Rail & PWM Buck Controller: The standby controller (often a TPS series IC) must generate +3VALW and +5VALW before the power button is pressed. If these rails are missing, check the Enable (EN) signals and the LDO outputs. High heat near the EC chip often indicates a shorted +3V_LDO line, usually caused by a faulty KB9022 KBC.
- Power-On Sequence & BIOS/EC Firmware: If the power LED blinks but the board doesn't post, verify the RSMRST# (Resume Reset) signal from the EC to the PCH. If RSMRST# is high but PM_SLP_S3# remains low, the issue may be a corrupted BIOS or ME Region. Always backup your original dump before flashing a clean ME region BIOS to this board.
Free Schematic / Boardview Download
📥 Download ACER ASPIRE S5-371 S5-371T COMPAL LA-D591P B3ZMS REV 2.0 Schematic / Boardview
Direct file link. Verified clean archive.
Need Additional Repair Assistance?
Explore our technician resources:
- 🛠️ Diagnose No-Power & Short-Circuit faults step-by-step: Interactive Laptop Diagnostic Lab
- 🛒 Original Replacement Motherboards & IC Components: Official Spare Parts Mega Store
