PDF circuit diagram of the MSI MS-7399 motherboard, version 3.0, around 1.1 MB in size. The name carries no chipset or date information. MSI uses the MS-7xxx pattern for its desktop boards, with the trailing number marking the revision. Technicians use it to trace power rails, follow the power-on sequence, and identify which regulator or capacitor sits on a shorted net. Check the silkscreen version on your PCB; if it reads something other than 3.0, find the matching sheet set among the other MS-7399 revisions.
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 @pepeelectronica. 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.