You can request what's known as a service manual from Behringer. But they usually don't have those over to end-users. What type of repairs do you want to perform?
An authorized service center will have access to all you need, replacement parts with corresponding part numbers and values and schematics. Here's the link:
http/www.behringer.com/EN/Support/Service-Information.aspx
or for placing parts special orders....
http/www.instrumentalparts.com/behringer-parts.html
You should be aware that with most modern electronics, repairs are normally done at the board level. Meaning, they will replace the entire PCB instead of bits at the component level like SMD resistors, caps, chips, etc. And so many parts will not be available from the manufacturer and you'll need to hit Mouser.com or Digikey for generic and common replacement parts.