When connecting CAVS DK3 Digital Karaoke Mixer, you need to install the PL2303 USB-Serial CH430 driver in your karaoke player, such as CAVS JB-199 III, CAVS Karaoke Laptop, CAVS Karaoke Touch Screens, or any PC/Laptop installed with the PlayCDG KJ Deluxe 64 LT Karaoke program. Attached is the PL2303 driver. Download and install into your karaoke player. You should also reboot your karaoke player before connecting the DK3 mixer. For the instruction on how to connect the DK3 mixer to a karaoke player, go to www.cavsusa.com/dk3mixer.php.