Churches with well-functioning lines of communication between pastoral/worship staff and the tech team tend to not only communicate when there are problems. Communication works best if it's regular, open, honestand two-way.
If you're not already doing a post-service review, this might be a good place to start. It should involve the key leaders in the various parts of the service: from the teaching pastor, the worship leader, and the tech team leader for that service.
Discuss what went well, and what could have used improvement. But also listen to the reason why something didn't go well.
Pastoral and worship leaders tend to throw things into the service at the last minute, and frequently what seems like a small request is a much bigger deal than you may be aware of. If what tends to go wrong is related to things that were added or changed at the last minute, be open to suggestions on how to make this work better, such as planning further ahead, or seeking input on the ramifications of making the request.
Also, communicate early. When does your tech team find out the makeup of the worship team for the upcoming weekend? Do they get notified of what is going to be happening earlier in the week so they can begin setting up correctly when they arrive (usually first) Sunday morning? Or, are they wasting valuable time setting up for a band that won't end up playing that week? If so, then you will have a tech who needs to scramble in order to recover and will go into both the rehearsal and service frazzled instead of mentally prepared to focus and mix well.
The technical ministries are usually far more complicated then it may appear. Techs like to be organized and prepared so they can do their best in supporting the service. Would you be thrown for a loop if thirty minutes before the service started you were asked to preach on a different topic? Or, as a member of the worship team, would you be a bit disconcerted if were handed a list of new songs that were to be played that morning instead of the ones you practiced all week?
Would you be able to do your best if either of these things happened? Likewise, keep your tech team in the loop and make them a part of the planning process for events and services.
Next time, we'll talk specifically about dealing with problems.