I did a setup the night before a gig once for an outdoor event. I had a 12 channel self powered Behringer mixer placed on top of my amp racks that were under the stage. It was going to be used as a side fill and center fill mixer/amplifier. Well the city " forgot " to turn off the sprinkler system that night. Needless to say my entire PA was given a free midnight bath compliments of the city. Even the stuff under the stage wasn't safe. There was a rather nice number of expletives coming from me the next morning........
I took a rather large chance knowing that the power amps would be fine ( they didn't get any water shot straight in ) in hopes the little mixer that could would fire up! Well it did and was happy to do it's duty!!!!! The only thing that gave me an issue that day was my saturated Stage snakes. They were rumbling, crackling and burping for a couple hours until they dried out. Luckily all was fine by show time, but what a scare.
Conversely I was caught by a surprise rain storm in the Bahamas ( not really : ) ) for a gig I was doing outdoors at the ocean club. The A&H ZED mixer was only caght by a little runoff water from the nearby tree. Needless to say I should have left it on. I turned it off and it never did come back to life. It fried the power supply. It goes to show that sometimes the non-modular designs with the boards having the bulk of sensitive parts not facing in the direction of potential water introduction, may actually withstand the elements a little better.