Lac391p Schematic Portable | Apw70

If you have a non-working board, use a multimeter in continuity mode:

workstation. Using a schematic for this board is essential for high-level troubleshooting, such as diagnosing power failures or short circuits. Core Components & Layout

: The ZBook uses a removable graphics module. Components near this slot, like the Q33 transistor , often fail. The schematic shows exactly what part to solder back into place. Tools Needed for Repairs

Locate the dual 3V/5V PWM controller chip on the schematic. Check for the following essential inputs: Must read ~19V. apw70 lac391p schematic portable

I also found a result from "remont-aud.net" about "HP ZBook 17 G3 Шасси (Main Board): APW70 LA-C391P". This seems to be a Russian site offering BIOS or firmware.

The PWM controller produces the 3.3V and 5V standby voltages required for the EC.

This technical guide breaks down the architecture of the LA-C391P motherboard, maps out its critical voltage rails, and explains how to use the schematic for efficient diagnostics. Motherboard Overview and Specifications If you have a non-working board, use a

However, I can suggest some possible sources where you may be able to find more information:

Uses a modular MXM (Mobile PCI Express Module) slot, allowing for swappable high-end NVIDIA Quadro or AMD FirePro workstation-class GPUs.

Enables tracing signals between the APW70 , KBC, and CPU. 5. Tips for Portable Repairers Components near this slot, like the Q33 transistor

Always start on page 2 or 3 of the PDF. The block diagram gives you a birds-eye view of how the system buses interconnect, identifying which page numbers host specific elements like the charging circuit, audio codecs, or BIOS chip.

Result 0 from the same search is a "component replacement" thread on HP's community forum, which mentions "APW70-LA-C391P" and a broken LED near the power supply input. This confirms the motherboard model.

Operational voltages for the platform controller hub embedded inside the Intel SoC.

Check the current-sensing resistor (usually labeled as R22 or PRXX near the charging area) for the full 19V B+ rail . If this rail reads 0V or pulses, an input MOSFET is likely shorted or the charging IC has entered protection mode due to a downstream short circuit. Always-On Rails (+3VALW and +5VALW)

Pressing the power button drops the ON/OFF# signal to 0V momentarily. The EC registers this transition and sends a wake signal to the SoC ( PM_PWRBTN# ).