La-f952p Schematic Jun 2026

Fault 1: Completely Dead Laptop (No LEDs, No Response to Power Button)

Memory power rails activated after pressing the power button.

Measure the resistance on the coils (inductors) for +3VALW and +5VALW . A dead short on the 3.3V coil often implies a destroyed PCH or a dead EC chip.

The specific voltage levels (e.g., 19V, 3.3V, 5V, 1.05V) needed for different circuits.

The main BIOS chip or the EC ROM can suffer from SPI data corruption. The board will have always-on voltages, but pressing the power button will result in zero behavior. Powers On, No Display (Caps Lock LED might blink)

Fan spins, power LED lights up, but the screen remains black.

The charger injects 19.5V into the board. This voltage passes through the input protection MOSFETs (managed by the charging IC) to become the primary system rail, usually labeled as or +19V_A .