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The transition of the SLP signals acts as an enable trigger for the secondary voltage regulators: +1.35V (DDR3L Memory Rail) +1.0V / +1.05V (SoC Core/VCCST/VCCIO helper rails)
: Tracing the "Main Power" (B+) line using the schematic helps identify shorted capacitors or MOSFETs that prevent the laptop from powering on. No Display/No Boot
: Designed for Intel mobile architectures (typically 6th Gen Skylake in the ZBook 17 G3). apw70 lac391p schematic portable
Locate the two input N-Channel MOSFETs near the charging IC. Check if the Gate voltage is being pulled up to roughly 25V by the charging controller. If the gate voltage is low, replace the charging IC or check its ACIN/ACOK pins. Step-by-Step Diagnostic Strategy Using the Schematic
Features multiple RAM slots, dedicated GPU options, and specialized power management circuitry to handle workstation-grade power loads.
When repairing a portable device using the LA-C391P motherboard, follow a structured diagnostic workflow. Visual Inspection Many members have archives of HP/Agilent internal documents
The DC-in circuit uses two P-channel MOSFETs configured back-to-back to prevent reverse polarity and isolation failures. The charging IC (often an Intersil or Texas Instruments variant) monitors the current via a low-resistance shunt resistor. If a short circuit occurs downstream, the gate drive voltage to these entry MOSFETs is cut off instantly. The Standby Power Circuit
When working with the motherboard using its schematic, keep these points in mind:
I need to gather information about this schematic. I should search for "apw70 lac391p schematic portable" and related variations. I'll also search for "APW70" and "LAC391P" separately to understand what these terms refer to. I'll also search for "APW70 laptop schematic" and "LAC391P power supply schematic". search results for "apw70 lac391p schematic portable" yielded no direct results, but I found several relevant links from other searches. Locate the two input N-Channel MOSFETs near the charging IC
While exact schematics are proprietary, the implementation of the usually follows a standard design topology. A. Input Stage ( VINcap V cap I cap N
or similar power ICs highlighted in the board's power rails section. Short Circuits
The DC jack feeds 20V into the board. This voltage passes through the input protection reverse-polarity MOSFETs. Once cleared, it becomes the primary high-power rail, usually designated as or P20.0V . This rail distributes power to all buck converters on the motherboard. Always-On Rails (LDO and Standby)