Service manual for the Audio Pro Ace Bass B1-39 subwoofer, a compact 272 KB PDF that likely holds the core amplifier schematic and perhaps a parts list. Use it to trace the input, filter and power amplifier path, check the supply rails and identify failed output devices or protection parts in the self-powered cabinet. The B1 series shares design ideas across models, so check that the board revision and part values match before using it on a B1-45 or other variant. Unplug the unit and drain the capacitors before probing.
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 @pdf_servicemanual. 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.