As far as I know, no manufacturer supplies laptop circuit diagrams to outside parties, except Panasonic for the Toughbook series. All the other schematics out there are leaks. Automotive manufacturers only supply wiring diagrams of the body wiring harnesses. The only electronic assemblies in cars you can get a circuit diagram for are radios; ECU internals are jealously guarded. Even in the consumer electronics industry, manufacturers don't tell you how to buy parts through components distribution. They either sell you the parts at humongous markup or direct you to their authorized parts dealers who buy them from the product manufacturer, not the component manufacturer, again at huge markup. Most of the chips in a laptop aren't available through components distribution at all because the distys would never be able to sell enough pieces to justify a minimum order from the chip maker.