Apple iPad 4 boardview in BVR format, 233 KB, with no logic board number in the name. Load it in FlexBV or another viewer that reads BVR to see components, nets and pins on the board, useful for diagnosing no-power faults, charging problems or shorts on the main rails. Because the iPad 4 came in Wi-Fi and cellular versions, confirm that the layout matches your unit by comparing the 820 board number and the placement of major chips before probing or replacing parts.
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 @SMART_PHONE_SCHEMATICS. Enginerys does not host this file.
How to open a .bvr file
Text boardview from the BoardView R family of tools, seen for Lenovo, MSI and Clevo boards.