I had the same issue an hour before a show started. Everything was set up and then it went crazy. Everything that was connected to console began to hum around 60hz. Thankfully, I also have the rack mixer and my main out puts are routed from the console through AVB to the rm. I have aux few subs from the console so I ended up having to use an aux out of the rack mixer , and controlling it with an iPad. It was an absolute night mare. Have you gotten resolution on this yet?