MSI MS-7A39 motherboard schematic at revision 2.0, a PDF of about 1.69 MB. A revision 1.0 drawing of the same board also circulates, and the two may differ in component placement or values, so read the revision off the board first. Inside you will find power rail generation, CPU VRM controller wiring, DIMM termination, the BIOS flash connection and I/O routing. A repairer uses it to trace why a rail is absent, measure expected voltages at test points or find the source of a short. Opens in any PDF viewer.
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 @afsschematicfree. 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.