Lad402p Schematic Top Exclusive

Isolate individual power inductors (coils) by desoldering them to divide the board into isolated testing zones.

Essential for diagnosing battery communication issues or thermal sensor errors.

The central zone of the top-side schematic is dominated by the . Radiating outward from the CPU are the high-current inductors (coils) and MOSFETs responsible for the core voltage rails: +VCC_CORE : Delivers primary power to the processor cores.

Coil DE-energized (Rest state):

Active state transitions via the ACPI (Advanced Configuration and Power Interface) protocol. Power Sequenced States of the LA-D402P lad402p schematic top

This board is used in at least two distinct Dell laptop lines:

| Symbol | Part | Typical Value | Function | |--------|------|---------------|----------| | | Input Decoupling Capacitor (X7R ceramic) | 10 µF – 22 µF, 10 V | Smooths out supply ripples, provides a local energy reservoir for transient load spikes. | | R1 | Series Input Resistor | 0.1 Ω – 0.33 Ω (1 % tolerance) | Limits inrush current when the device powers up, helps protect the LAD402P’s internal MOSFET from stress. | | D1 | Reverse‑Polarity Protection Diode (Schottky) | 1 N5819 or similar | Prevents catastrophic damage if Vin is accidentally connected reversed. Schottky is used for its low forward voltage (≈0.3 V) to minimize loss. | | C3 (optional) | High‑Frequency Bypass (0.1 µF) | 0.1 µF, 6 V | Placed close to the regulator pins to shunt HF noise to ground. |

The LAD402P is internally compensated for loads > 200 mA. If you anticipate lighter loads (< 200 mA), increase C2 (e.g., to 2 µF) or add a small series output resistor (R5, 0.1 Ω) to guarantee sufficient ESR for stability.

The LA-D402P utilizes an ultra-dense, multi-layered PCB design optimized for the chassis of the premium HP Spectre line. Specification Compal Electronics Motherboard Model LA-D402P (often paired with sibling board LA-D401P) Compatible Devices HP Spectre 13-v, 13t-v Series (e.g., TPN-C127) Processor Support Intel Core i5-7200U / i7-7500U (Kaby Lake-U BGA) System Memory Radiating outward from the CPU are the high-current

Specialized online archives like Laptop-Schematics or structural document networks like Scribd's Compal Schematics Sections often host comprehensive design manuals for independent repair laboratories.

The device itself is a (Vin, Vout, GND) with an internal current‑limit and thermal protection. The external “top” schematic essentially provides biasing, compensation, and protection so that the regulator can operate safely and with low noise.

: A laptop that illuminates its charging LED but refuses to trigger a full power-on sequence often suffers from a corrupted flash chip. Repair requires removing the EEPROM chip from the top layer and rewriting it with a clean dump utilizing an external programmer.

NO-1: Terminal 13 ----/ (open) ---- Terminal 14 NO-2: Terminal 23 ----/ (open) ---- Terminal 24 | | R1 | Series Input Resistor | 0

This motherboard platform, code-named , is designed to support the Intel Alder Lake-P (ADL-P) CPU architecture and DDR5 memory . Because it powers workstation-class laptops, the power delivery system is exceptionally complex.

Based on its performance, features, and design, I would rate the LAD402P schematic top as follows:

To help narrow down your repair or design review, are you analyzing a on this board (such as no power, missing video, or charging failure)? If you have a specific component or circuit net name you are trying to locate, please share it. Share public link

Now let’s unpack each element.