JVC KW-AVX800 CD Player "pre sub output check" Questions

...pre-outs for an amplifier they are mislabeled. The subwoofer out is labeled as the front output and it is off when shipped. Connect to rca out labeled as the sub and you should get sound. The sub out ...

...sub sounds great, but the pre outs the left one no sound comes out of it both of them, left front and left rear, the right ones work fine, all of this happened all of a sudden 2 weeks ago....had my ...