Guide to the LA-D402P Schematic
1. What is the LA-D402P?
- Board Number: LA-D402P (printed directly on the PCB)
- Common Models: Lenovo IdeaPad 330-15AST, 330-17AST, 330S-15AST
- Key Components: AMD A9/A6/ E2 series CPU, AMD Radeon R5 graphics, internal battery management, USB-C power delivery (on some variants).
- Receives 3.3V standby power.
- Monitors the power button pin.
- Sends "PSON#" signal to enable the main power rails.
7. Tools You Will Need
- Multimeter (with continuity/diode mode)
- DC power supply (for current limiting)
- Oscilloscope (to check power sequencing or SMBus)
- Micro-soldering station (for MOSFET/IC replacement)
- Boardview viewer (OpenBoardView – free)
- Connect the power supply.
- Check for 3.3V at the KBC (Super I/O) chip. If missing, trace back to the 3.3V generator.
- Press power button.
- Check if the KBC sends a signal to enable the PMIC.
Short Circuit Check (Diode Mode):
