[CyberDaemon]

Alexandrovav, смотри, что нашел

The diagnostics can be executed using the remote commander (Remote Control Mode 3) and monitor. To execute the service mode, connect the VIDEO OUT (L2 OUT) connector to the monitor. Connect the AC power cord to the power outlet. A message, "WELCOME" appears on the display panel of the main unit. Keep holding down the "REC PAUSE", "REC STOP" and "REC" keys, of the main unit (about 10 seconds) until the screen appears on the monitor display. Either "OK" or "NG" appears on the monitor screen while the diagnostics is in progress. You can judge the respective device or its peripheral from the message of either "OK" or "NG" on the monitor screen. When an abnormality is detected, the diagnostics is stopped at that moment and you can select to proceed the diagnostics or to stop it. Use the keys on the front panel of the main unit to operate the diagnostics.

Это для HX710, но вроде особой разницы между HX710 и HX910 нет.