NAD M52, Quick Setup Manual, Page: 4 / 18

M52 References for Service Manual (Rev. A)
M52 LED Indication
standby: power LED amber, HDD LEDs off
power up: power LED steady blue, HDD LEDs interleaving flashing red/blue
short ‐ time power loss (e.g. USB unplug and plug back in a second or two) : Power LED steady blue, HDD
LEDs flashing red/blue at the same time
unit active healthily: all LEDs steady blue and the unit can be accessed and recognized
unit has invalid RAID set: all LEDs steady blue but the unit can't be accessed or not recognized.
rebuilding: LED of the rebuilding HDD flashing blue
rebuild success: LED of the rebuilding HDD steady blue
rebuild failure: LED of the rebuilding HDD flashing red
individual disk healthy: LED of the HDD steady blue
disk failure: LED of the HDD flashing red
disk missing: LED of the HDD steady red
NOTE:
1) “unit has invalid RAID set” may be caused by inserting a HDD that was part of other RAID set
unit. Wiping the last few sectors of the HDD will solve the problem (see “Rebuild” note 1). Or if
it’s caused by something else, re ‐ initialize and reconfigure the RAID set is required which will
cause the data loss.
2) “disk failure” may be caused by SATA port failure if the disk itself is healthy. Replacing the failed
disk with a new one or unplug and plug back the failed disk, and rebuild RAID array will solve the
problem (see how to rebuild RAID array section).