Pioneer DJ DDJ-REV1 Sound Issue

I recently purchased the Pioneer DJ DDJ-REV1, and noticed after two months that sound no longer comes out of the RCA cords into the speaker, defeating the purpose of having a controller to play music for events. Instead, when connecting the RCA cords to the speakers' inputs, it creates a flat buzzing sound. 

 

I ran a test on another Pioneer controller using the same RCA cords / inputs, and the sound from controller to speaker worked. This confirmed the issue with the DJ DDJ-REV1 Serato controller that I recently purchased.

 

This has been frustrating! Is there something I'm missing? Thank you!