WD DL4100 not rebooting

Hi there

I have been using a WD DL4100 for 7 years. Configuration is as follows:
WD DL4100 with 4 x drives: WD Red 3 TB x 2, WD Red 4 TB x 2
Configured for Raid-5
Upgraded to OS5

The unit has been mainly used to capture backups, and stream home videos to our Smart TV. Unit has been running fine for 7 years, except for two failed WD Red 3 TB disks around 2019 that were replaced with WD Red 4 TB disks.

Around 2nd or 3rd April 2023, we couldn’t connect to the unit.

The display showed it was on standby but had no connectivity. I tried restarting the unit by pushing the button on the front panel. The unit will not boot up. Fan is running, ethernet lights at the back are flashing, 4 x Blue LED disk lights are solid on, display is blank. Unit keeps turning off and on after approximately 4 minutes.

I also tried the 4-second and 40-second reset procedures to no avail. I also left the unit unplugged for several days, but it will still not restart.

WD Support led me through various tests, but finally reached the conclusion that the unit was “non-functioning” and because it was past the warranty period there was nothing they further that could be done.

Perhaps it is purely coincidental that my DL4100 stopped working around the time of the mycloud outage. Based on the date of the last Windows backup taken, the unit was operational on 2-April-2023.

I wonder if anyone else has had success in recovering from such a situation with their DL4100 or similar NAS?