Operation Manual MA 428100460 Rev.7 Ver.1 11 12/15Rear Panel ConnectionsFigure 1– Rearview of the MA 421: Power switch 10: CD Input2: Power socket 100-240 VAC / 50-60 Hz 11: Speaker left channel3: Network socket 12: Speaker right channel4: USB out socket 13: Bone conduction receiver5: USB in socket 14: Insert phone left channel6: Pat (patient response switch) socket 15: Insert phone right channel7: Talk back microphone socket 16: Phone left channel8: Mic (live voice microphone) socket 17: Phone right channel9: Mon (monitor phone output) socketPlace the MA 42 on a stable counter or table. Plug the power cord into thepower socket on the rear panel. Connect all accessories with the adequatesockets as shown above. Plug the power cord into a grounded outlet.Turn on the instrument with the power switch which is located at the rightside of the MA 42.Note: A device should always be off when inserting or removing an accessoryfrom the rear panel connectors.The device performs its initialization and auto calibration. Please wait until thetest screen appears, this can take up to 60 seconds. If an error is detected thetest is stopped and a description of the error is shown on the display. In thiscase, please contact your local dealer or service.11 13 14 1615129 108765421 3 17