Thanks, ArticCynda, for the link. Yep, Dave certainly did a pretty amazing job in doing a reverse engineering on the Rigol DS1054Z oscilloscope.
Incidentally, someone posted a request about a year ago, requesting how to do it using the manual approach (see below thread link), which the above should be helpful.
if your only have one or two sited pcb boards you can reverse engineer with some data sheet lookup and guess, but if it is a multilayer it is not always easy to do. that why it is good to function and block diagram in your head.