Series 16/18/160/180-Model C Maintenance Manual, GFZ-62755EN ...

8. TROUBLESHOOTING B–62755EN/018.19ALARM 404 AND 405(*DRDY SIGNALTURNED ON) Alarm 404 CausesDRDY signal is turned on before MCON signal is turned on. Or DRDYis not turned off after MCON signal is turned off.1 Servo amplifier is faulty.2 Between servo amplifier and main CPU or between servo amplifierand option 2 board is faulty.3 Main CPU or option 2 board is faulty.CAUTIONWhen the main CPU board is replaced, all the data stored inmemory is lost. Set the NC data again, referring to chapter3 “data input/output”.· Main CPU board· Option 2 boardServo amplifier ( series)DVSERVOx–10*MCOMJSnB–10RV RLY MCCT1–5,6100VACRV–20*DRDY–20DVFrom 1st axis to 4th axis are main CPU board. 5th axis or later are option2 board. Alarm 405 (Referencepositin return isabnormal) CausesThe grid signal is not turned on when the automatic reference positionreturn by G28 is completed.Main CPU board or Option 2 board is faulty.CAUTIONWhen the main CPU board is replaced, all the data storedin memory is lost. Set the NC data again, referring tochapter 3 “data input/output”.348