SQ6 dropping

Once in a while, I’ve had a channel just drop for a bit. Yesterday, I wasn’t at the board, all audio dropped for about 5 seconds. The guy at the board said that there was no signal on any of the channels. We had 5 in use, 3 of them local. Any idea what could be causing it?

When he said there was no signal, did all the metering on the board stop showing any levels?

That’s correct. No levels on the meters. And then it just came back.