Desktop motherboard schematic for the Biostar A55MLC2, listed with board code AA55K-M1S at revision 7.1, in an 805 KB PDF; the index tags the brand as ECS. The A55 in the name suggests an AMD A55 chipset board, though the document itself should confirm it. Use it in any PDF reader to trace the CPU VRM, standby and main rails, Super I/O and BIOS chip connections when a board fails to power on. Check that the revision printed on your PCB matches 7.1 before relying on values.
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.