I've been using my HD500 for years. Last night at a gig there was no unbalanced output. Ugh! Tuner worked, all patches showed up. Today I checked again and no unbalanced output on either Right or Left. I checked the balanced XLR and headphone outputs and they all work. Since both Right and Left outputs stopped, it does not seem that there would be a physical connection issue inside. Could it be a software glitch? Is there a HD500 reset? Any suggestions as to what to look for?