To get the actual schematic diagrams, you should look at the official documentation:
If you are trying to repair a broken Pi, the "Reduced Schematics" provided by the foundation are often not enough because they omit the specific capacitor/resistor values in the power sections. raspberry pi schematic diagram
If you are looking at a schematic PDF or trying to understand how the board works, it is generally divided into these "Sheets" or functional blocks: To get the actual schematic diagrams, you should
Always download the "Raspberry Pi 4 Model B Schematic" and the "Mechanical Drawing" together. The schematic tells you what the signals do; the mechanical drawing tells you where they are physically. For hardware integration or coding, use the official
For hardware integration or coding, use the official found on the Raspberry Pi datasheets page. For designing your own carrier board, use the Compute Module 4 datasheets , which are fully open-source.