19Compensation of interference with balanced connectionsMaintenanceThe DAP Audio Core Mix-4 USB requires almost no maintenance. However, you should keep the unitclean. Disconnect the mains power supply, and then wipe the cover with a damp cloth. Do not immersein liquid. Do not use alcohol or solvents.Keep connections clean. Disconnect electric power, and then wipe the audio connections with a dampcloth. Make sure connections are thoroughly dry before linking equipment or supplying electric power.TroubleshootingDAP Audio Core Mix-4 USBThis troubleshooting guide is meant to help solve simple problems. If a problem occurs, carry out the stepsbelow in sequence until a solution is found. Once the unit operates properly, do not carry out followingsteps.1. If the device does not operate properly, unplug the device.2. Check power from the wall, all cables, connections, etc.3. If all of the above appears to be O.K., plug the unit in again.4. If nothing happens after 30 seconds, unplug the device.5. Return the device to your DAP Audio dealer.