DDJ SX urgent help needed, only sound output on one channel

Hello, having a problem with my SX. I haven't changed any settings and it has always worked perfectly. For some reason Channel 1 is the only channel outputting sound. All the others the LED indicators are lighting up as they should, the cue function is working as it should, but just no sound coming out of the master other then channel 1. I have tried installing the latest firmware etc but it hasn't helped. I have gigs almost every night at the moment and can't survive without this. And sadly living on a small island in Greece there's not much hope for just going to a service centre. Please help!!!