Osamu2-dis-kb-hpc Mv-mb-v1 Schematic Jun 2026

The motherboard schematic is a vital blueprint for diagnosing, repairing, and understanding a widely deployed hardware architecture found in various budget-friendly HP laptops , such as the HP 15-D and HP 255 series . Manufactured by Inventec or Quanta (denoted by the code string format), this motherboard combines an AMD processor or low-power Intel platform with dedicated (Discrete) graphics.

Locate the display output select resistors on the schematic. Move specific low-tolerance configuration resistors from the DIS pads over to the UMA layout pads. Reroute Display Lines osamu2-dis-kb-hpc mv-mb-v1 schematic

If you but know the project source (GitHub, Hackaday, etc.), share the link – I may be able to locate it or reconstruct the likely design. The motherboard schematic is a vital blueprint for

| | Purpose and Key Components | Relevance to the OSAMU2 board | | :-------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Power Input & Charging Circuit | Manages the power from the DC adapter and battery. Includes input MOSFETs (PQ41), charging ICs, and main power rails (VIN, +VALW). | Critical for diagnosing 'no power' issues. This section is often where the first faults occur. The board uses non-standard P-channel MOSFET configurations. | | Embedded Controller (EC) | The EC is a dedicated microcontroller managing low-level operations like power sequencing and keyboard control. The schematic shows its connections. | Many power-on and startup problems are rooted in the EC's logic (e.g., an EC like KB3940Q A1). A schematic is needed to probe its input and output lines. | | CPU & Chipset Power Rails | Outlines the intricate voltage regulator module (VRM) that supplies power to the processor (SR1LV - Mobile Pentium N3510) and the chipset. | Ensures the delicate and exact core voltages are correctly sequenced and stable. Important for diagnosing 'turns on but no display' faults. | | BIOS / SPI Flash | Shows the connections to the BIOS chip (e.g., 25Q32FV, 25Q80BV), which holds the firmware for the board to boot. | A corrupted or incorrectly flashed BIOS is common. The schematic helps in identifying the correct pins for programming. | | Peripheral & I/O Sections | Details the circuits for system memory (RAM), display (LCD/LVDS/eDP), USB, audio, and other connectors. | Useful for troubleshooting secondary issues like no audio, non-functional USB ports, or a dim/no display after the board powers on. | Includes input MOSFETs (PQ41), charging ICs, and main

Serialized Interrupt Request for communication between the chipset and peripherals.

Test for 19.5V on the drains of the DC-in protection MOSFETs. Check if +3VPCU is active on the EC chip pins. Corrupted BIOS Firmware or Bad RAM Rail

If any of these rails fail to rise to their native amplitude, the motherboard stalls, resulting in common symptoms like a power light on with no display. Common Fault Diagnostics and Schematic Troubleshooting