Xdj-r1 soundcard problems?

I've had the xdj-r1 for about a year and it was working fine until recently. I think i'm having some soundcard problems. The volume is not what it used to be and when i turn it up the sounds starts making cracking noises especially when i try some of the fx (like echo). I've updated it to the latest firmware and i tried both master outs (xlr & rca) with different studio monitors (krk & m-audio). So i definitely think its a soundcard issue. Has anyone had the same problems? I could really use some help because my warrenty ran out.