User’s Manual13Troubleshooting for no power- Check if LED light on the front is turned on.- Make sure the power cord connectors on both ends are firmly attached.Please refer to the webpage, www.dzonei.com for more detailed informationfor the troubleshootingUSB (Firmware upgrade) & RS-232 (Remote Control)USB : You can upgrade firmware by USB easily when new firmwareis released.( FAT32 file system is only available in USB)RS-232: RS-232 is capable of external control via serial port providedcontrol protocol by Digitalzone.