Schematic in PDF for project PS10A, a PMP build dated by the code 0123, likely a pre-mass production release. The name gives no brand or board number, and the code resembles the Potomac PT10A naming from the same family. A diagram like this is used to trace voltages, locate components and confirm signal routes. Because pre-production designs can differ from retail boards, check the revision and part markings on the PCB before trusting 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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)