Apple iPad 2 schematic in PDF format, roughly 637 KB, with no board number or revision stated in the file name. Since the iPad 2 came in Wi-Fi and cellular versions, confirm that the logic board in front of you matches the pages, for example by comparing component designators. The circuit diagram is used to follow power rails from the battery and PMU, check the charging, backlight and USB paths, and look up which lines a connector pin carries. Use it alongside a boardview, if one is available, to locate the parts you read about here.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @BoardSchematic. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.