Output Loss

I've been having a problem with my Kemper. The output has started dropping out while I'm playing. It's been happening for a while but would always come back. Now it's dropping out and not coming back even with a reboot. Two weeks ago it stopped working for a couple of days until I updated to 2.7.
Tonight it's done it again. Tried different cables, different outputs and inputs. The output light on the front of the amp is still flashing, just no sound. I've got a pretty big gig in two weeks and can't afford to have this thing just drop out on me in the middle of a set.
Anyone else had this problem?

Thanks man