Do you know anyone who might be able to take pictures? (sarcasm mode)
Anyhow, if someone blew out your system, they may have left each solenoid unscrewed 1/4 or so turn. That's how you can force one station on, unscrew the solenoid a bit.
When you turn it back on, you might need to go into the box(es) and make sure each solenoid is snug.
I don't know, but this may be a ploy to get you to "hire" them for $xxxx to "fix" your system even when it isn't broken. Just sayin'... I'm sure there are competent and honest sprinkler service dudes out there. In fact, my buddy is one of the good guys, and tells me about the crap he finds that others left as a "problem".
Hope you get it fixed before your yard gets fried. Mid 90's this weekend baby!