Using the schematic, follow this flow:
Warning: Some WD My Book drives with E93839 boards have hardware encryption on the USB bridge. Bypassing the PCB without unlocking will yield scrambled data. The schematic will identify whether an encryption chip (e.g., Winbond or Macronix flash) is present. E93839 Motherboard Schematic
The most common reason professionals search for the "E93839 schematic" is data recovery. When an external hard drive’s USB bridge fails, the drive inside may still be functional. The schematic allows a technician to: Using the schematic, follow this flow:
Because "E93839" is the board code, searching specifically for that string can sometimes be difficult in public archives. Schematics are usually indexed under the laptop model name. Warning: Some WD My Book drives with E93839
You should search for: "Dell Inspiron 15 3542 Schematic" or "Wistron 13269-1 Schematic" (Wistron is another manufacturer for these boards, and the boards are often interchangeable/identical in layout).
Important Note on Safety & Legality: Schematics for laptop motherboards are considered proprietary intellectual property by the manufacturers (Dell/Foxconn). They are not typically released to the public. While they can sometimes be found on repair forums or electronics repositories, I cannot provide a direct download link to copyrighted material.