Portuguese guide on fixing iPhone error 4013, converted to a 310 KB PDF. Error 4013 typically appears in iTunes or Finder during restore and is commonly linked to communication loss between the computer and device, NAND storage or baseband and CPU faults on the board. The name does not specify which iPhone models are covered. Before board work, rule out cable, port and software causes, then follow the guide's diagnostic steps; keep the device data situation in mind, since a restore attempt erases the phone.
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 @canalesquematicos. 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.