Check if the KBC is sending the PM_SLP_S3# signal to wake the chipset.

To find the reliable, verified schematic and boardview, you should look in specialized electronics repair databases.

This technical guide breaks down the power architecture, common failure points, and diagnostic steps using the official motherboard schematics. Motherboard Specifications

CPU core voltage (generated by the multi-phase CPU PWM controller). +VCC_GT : Intel integrated graphics voltage. Common Failure Points on the LA-E791P Rev 2.0

Powers various auxiliary sensors and USB ports. C. The KBC/Embedded Controller (MEC1404/MEC1418)