Korg X5D Low Volume Problem

[deshwani]

My Korg X5D having low volume problem when I put it on stage with my band with all sound system, When I play it in single amplifier its volume is normal not so high but when Put it on stage with heavy sound system with whole band my volume is too much low, sound operator even put his volume slide on max side but still sound is very low, it comes little bit increase when sound operator put it with XLR cable but still low, I asked with technician he said your sound ic is dead, but I don't think so it is sound ic problem, because if sound ic dead there would not any sound, volume slide is also okay as it is working from low to high and high to low, what can be problem anybody help me please? my email mwajahatw@gmail.com