English-language schematic for the LG D800, the G2 model on AT&T, in a fairly large 60.5 MB ZIP archive. The size suggests the package may include high-resolution drawings or a full service manual, though the name does not confirm this. Use it to trace power rails, check the charging and battery circuit, and find components on lines that read short to ground. LG produced several G2 variants under different D8xx codes, so make sure the device in front of you is a D800 before following part references.
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 @esquematicosparatodos. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.