crwdns2934241:0crwdne2934241:0 mayer

crwdns2934249:0crwdne2934249:0:

That's a broad subject.  Can you narrow it down to what you are trying to get info on in maintenance?

If it's Apple, here's a very good guide:  Apple_Training_Series_-_Desktop_and_Portable_Systems__3e

This is a PDF and I believe the last one Apple actually publish.  Do a web search and download it.

crwdns2915684:0crwdne2915684:0:

open