If you are repairing a Lenovo G570 that refuses to turn on, here is a step-by-step guide using the updated e93839 documentation:
The motherboard schematic for the e93839 is more than a PDF; it is a diagnostic tool, a parts catalog, and a time machine for vintage 2010s business PCs. As these systems flood the used market (often for under $50), the ability to repair them is a profitable niche. However, relying on a decade-old, incomplete diagram will lead to dead ends.