Wistron Olympus notebook motherboard schematic, board number 07258-3, with the PCB part code 48.4Y603.0SA in the name. Wistron labels boards with a five-digit project number plus a revision suffix, and the 48.xxxxx.xxx code is its printed PCB number. Engineers use this PDF to follow power rails, find test points and diagnose shorts or missing voltages. The -3 suffix denotes a specific revision; a -1 version also exists, so check the revision on your board before using component values from these pages.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.