The LA-H103P (also known as the Compal FL5C5/FL535/FL435) is the motherboard for the Lenovo IdeaPad S340-14IIL and S340-15IIL series laptops . Motherboard & Schematic Overview
This motherboard is designed for 10th Generation Intel Core "Ice Lake" processors (i3-1005G1, i5-1035G1/G4, i7-1065G7) and typically features UMA (Unified Memory Architecture), meaning it uses integrated Intel Iris Plus Graphics rather than a dedicated GPU . Platform: Compal FL5C5/FL535/FL435 . Revision: Most commonly found as Rev 1.0 or Rev 0.2 .
Memory Support: DDR4 SODIMM, often with 4GB soldered onboard and one expansion slot . Key Resources & Downloads
If you are looking for the technical "piece" (the schematic or boardview file), they are available through specialized technician databases: Resource Type Source / Link Schematic (PDF)
Available on RealSchematic or via tech forums like Badcaps . Boardview (.cad) Can be found on DeviceDB for Rev 0.2 . Video Walkthrough
Troubleshooting and schematic reviews are available on YouTube . Common Repair Context Technicians often seek the LA-H103P schematic to address:
Power Rail Failure: Identifying short circuits in the 19V primary rail or 3.3V/5V "always-on" rails.
RAM Disabling: In cases of faulty onboard memory, the schematic is used to find the "RC" (Resistor Configuration) straps to disable the onboard RAM and force the system to use only the SODIMM slot .
BIOS Issues: Finding the BIOS chip pinout for external flashing .
If you are performing a specific repair, I can help you find: The resistor locations to disable onboard RAM. The voltage test points for the power-on sequence. The pinout for the charging port or battery connector. Which specific part of the board are you troubleshooting?
is a Compal-manufactured motherboard used in Lenovo IdeaPad S340-15IIL S340-14IIL
laptops. It typically features 10th Generation Intel Core i3, i5, or i7 processors and integrated DDR4 RAM. AliExpress Schematic & Troubleshooting Guide
To use the schematic for repairs, focus on these critical power sections and sequences: Primary Power Input (19V Rail)
: The sequence begins at the DC power jack, passing through MOSFET switches and a current sense resistor to provide the main 19V rail to various integrated circuits (ICs). Always-On Voltage Rails : A key checkpoint is the presence of
rails. These are typically generated by an IC like the TPS 51020 even before the laptop is powered on. Power Sequencing lah103p schematic new
: For the laptop to boot, it must follow a specific power-on sequence from S5 (soft-off) to S0 (fully on). : Standby voltages (+3.3VALW, +5VALW) are active. S3/S0 State : Higher power rails like (CPU power) and RAM voltage are enabled. Core Voltage (+VCC_CORE)
: This is essential for the processor. The control IC adjusts this output based on identification signals (IDs) sent by the CPU. Where to Find Schematics
While a "new" official release version may not be widely public, technical archives often host these files: Digital Archives Schematics|Boardviews Archive on Telegram often list Compal LA-H10x series diagrams. Video Walkthroughs : Repair channels like Colombia Tech Schematic Electronics Repair Basic
provide visual guides for tracking these specific motherboard rails. Telegram Messenger Common Repairs for schematics|boardviews| ARCHIVE – Telegram 9 Sept 2023 —
(also known as FL5C5/FL535/FL435 ) is a Compal motherboard commonly found in the Lenovo IdeaPad S340-15IIL
series. Below is a deep report based on the schematic architecture for this board, focusing on technical specifications, power rails, and common repair points. 💻 Hardware Specifications is designed for 10th Gen Intel Ice Lake (IIL) processors. Processor: Integrated Intel Core i3/i5/i7 (Ice Lake-U)
4GB/8GB Onboard DDR4 + 1x SODIMM Slot (supports up to 20GB/36GB total)
Intel Iris Plus (Integrated) or NVIDIA GeForce MX230/250 (Discrete - optional) 1x M.2 NVMe SSD slot and 1x SATA 2.5" HDD/SSD connector I/O Controller (SIO): ENE KB9022Q or similar 128-pin chip ⚡ Critical Power Rails & Sequence
For troubleshooting a "Dead" or "No Power" board, follow this voltage measurement sequence: 1. Primary Input (VIN) +19V (B+): The main power rail distributed after the DC-in MOSFETs. Check Point: Measure the current sense resistor (usually labeled or similar). 2. Standby Voltages (Always-On)
These must be present even when the laptop is off but plugged in. 3.3V power for the Super IO (EC) and BIOS chip. 5V standby for USB and other peripherals.
3.3V signal to the Super IO to indicate it is ready to work. 3. Triggering & Secondary Rails
Once the power button is pressed, the following should activate in order: +1.2V / +1.35V: RAM Power (DDR4). +1.0V / +1.05V: PCH/Chipset Core. +VCC_CORE:
CPU voltage (only appears after all other rails are stable). Integrated Graphics voltage (appears last). 🛠️ Common Repair Issues Likely Cause No Power (Dead) Shorted Input MOSFETs Check PQB1/PQB2 for shorts to ground. Turns on, No Display Corrupt BIOS
Flash the 8MB/16MB SPI Flash chip with a clean ME region file. Not Charging Charging IC Failure charging controller. Keyboard Not Working KB9022Q Fault The LA-H103P (also known as the Compal FL5C5/FL535/FL435)
Check for liquid damage around the Super IO or ribbon connector. 🔍 Visual Reference & Diagrams
The internal architecture follows the standard Compal "Power Sequence" logic where the signal from the EC tells the Southbridge/PCH to wake up. 📂 Technical Resources If you need the full PDF for deep tracing, you can find the LA-H103P Rev 1.0 schematic and boardview files on technical forums like: BadCaps Forum (Free community-driven repair database) (Professional paid resource for verified boardviews) Laptop-Schematics.com (Direct purchase of PDF diagrams)
To help you further with a specific repair, could you tell me: What is the current symptom
? (e.g., no power, water damage, or turns on but no screen?) Do you have a multimeter DC Power Supply to take measurements? Are there any visible burnt components on the board?
Understanding the LA-H103P Motherboard Schematic The LA-H103P is a specific internal part number for a laptop motherboard, most commonly found in the Lenovo IdeaPad S340-15ILL series. A schematic for this board is a technical blueprint used by repair technicians and electrical engineers to diagnose, troubleshoot, and repair hardware issues. Core Functionality and Architecture
The LA-H103P schematic details the electrical architecture of a mobile system, typically supporting Intel's 10th Generation Core processors (Ice Lake). Key sections of this technical document include:
Block Diagram: High-level overview showing the connection between the CPU, system memory (DRAM), and major input/output (I/O) interfaces.
Power Distribution: Mapping of the "Power Sequence," which illustrates how the board transitions from an "Off" state to a fully powered-on state through various voltage rails (e.g., +3.3V, +5V, +1.05V).
Voltage Regulators: Detailed circuits for DC-to-DC converters that step down battery or adapter voltage for sensitive components like the CPU and RAM. Identifying Components in the Schematic
Technical diagrams like the LA-H103P use standard alphanumeric labels to help technicians identify physical parts on the printed circuit board (PCB): Label Prefix Component Type U or IC Integrated Circuits (e.g., CPU, BIOS chip, Power IC) R Resistors C Capacitors (used for power filtering) Q Transistors (MOSFETs used in power switching) L Common Use Cases for Repairs Technicians use the LA-H103P schematic primarily for:
No Power Issues: Identifying which voltage rail is missing or shorted to ground.
Water Damage: Locating corroded traces or components that need replacement based on their electrical values listed in the schematic (e.g., a "100k ohm" resistor).
BIOS Failures: Locating the specific chip designated for firmware storage to perform a re-flash. Resources for Access
Since these documents are proprietary, they are usually found on specialized technician forums or databases: Laptop schematic diagrams The Hard Truth (Important) If you are repairing
The LA-H103P schematic (also known as the EL5C3/EL531/EL431) is a technical blueprint for the motherboard used in Lenovo IdeaPad S340-15ILL and S340-14IIL laptops. For technicians and engineers, this document is an essential tool for diagnosing power failures, short circuits, and logic board issues. The Architecture of the LA-H103P
The LA-H103P motherboard is designed by Compal, an original equipment manufacturer (OEM) for Lenovo. It supports Intel Ice Lake (IIL) processors and features a complex power management system to handle various voltage rails.
Core Components: The schematic details the connections between the CPU, DDR4 memory, and the PCH (Platform Controller Hub).
Power Distribution: It maps out critical voltage paths, including the +19V primary rail, +3VS/+5VS standby rails, and the CPU VCORE.
Peripheral Interfaces: The diagram covers the wiring for the LCD connector, USB 3.0/Type-C ports, SATA interfaces, and the Keyboard/Touchpad controller. The Utility of Schematics and Boardviews
In modern electronics repair, a schematic alone is often not enough. Technicians typically use the LA-H103P schematic alongside a Boardview file.
If you are repairing a TV from 2018-2022 and see the LAH103P, understand this: It is likely a programmed microcontroller or a custom power ASIC.
Because the old schematic showed an open-collector output, technicians added pull-up resistors to 5V or 3.3V. The new schematic shows this is now unnecessary and harmful. The output is a true voltage output. Adding a pull-up will cause current sinking conflicts and non-linear readings.
R1 (External Pull-up Resistor):
C1 (Decoupling Capacitor):
R2 (Optional Filter):
Understanding how the schematic behaves is vital for debugging.
Why is this "Active Low" design used? It provides a fail-safe mechanism. If the wire to the sensor is cut, the pull-up resistor forces the line High, which is distinct from the "Active" Low state, allowing the system to detect a fault.
In the world of power electronics and industrial control modules, few components generate as much curiosity—and frustration—as the hybrid module labeled LAH103P. Whether you are an R&D engineer troubleshooting a motor drive, a repair technician working on a CNC machine, or a hobbyist salvaging parts from high-end Japanese industrial equipment, finding an accurate, clear, and new schematic for the LAH103P has traditionally been a nightmare.
Until now.
This article dives deep into the newly released, verified LAH103P schematic new revision. We will break down its internal architecture, explain its role in current sensing, provide a pin-by-pin functional analysis, and discuss how this new documentation differs from the fragmented, often incorrect diagrams circulating online.