Controlled by a synchronous buck regulator IC (typically a TI TPS-series or RT-series controller). Steps down B+ (19.5V) to clean +3VALW and +5VALW .
[DC-IN / Battery] ──> +B (19V Main Rail) ──> +3VALW / +5VALW (Standby) │ [System RAM Powered] <── +1.35VGS / +1.35V <────┼──> [Power Button Pressed] │ │ [CPU VCORE / Graphic Rails Awake] <──────────────┴──> +3V / +5V (Run Rails) The Primary DC-In and Charging Node (+B Rail) la-9413p rev 1.0 schematic
Look for "Power Tree" or "Power Sequence". Key pages: Controlled by a synchronous buck regulator IC (typically
Schematics like this are usually sourced from professional laptop repair forums and sites that specialize in motherboard diagrams. Key pages: Schematics like this are usually sourced
Once the power button is triggered, the EC broadcasts a series of power-good signals, changing auxiliary switches to release the , +5V , and +1.5V Run rails. Finally, the CPU PWM multi-phase buck controller energizes the +CPU_VCORE lines to clock the processor. 3. Common Failure Points on the LA-9413P Motherboard
Locate the power button connector pin on the schematic. Verify that pressing the button drops the voltage from 3.3V to 0V at the dedicated pin of the KB9012 EC chip. Problem B: Laptop Turns On for 2 Seconds, Then Shuts Off
Yes. The Intel version uses a different PCH (e.g., Bay Trail) and a different power management IC. The AMD version has an AMD A-series APU. Check the page titled "CPU Configuration" in your PDF.