Hello,
I have a DNS-323 (hardware version B1, firmware version 1.08).
Following a problem (e-mail sent by the NAS: Left Hard Drive Has Failed / Right Hard Drive Has Failed Sincerely, Your DNS-323), 
I have formated the two drives (2x1TB) and i have do a reset (restore to default factory settings) but the NAS still don't "see" the drives 

The NAS makes bizzarres regular noises ("clac"") (from the NAS, not from the disks)
Any idea ?
Total Drive(s):  0
Here are the logs:
System restore to factory default settings. 
2019/10/06
02:25:16
HDD2 Hard Drive Has Failed 
2019/10/06
02:25:20
HDD1 Hard Drive Has Failed 
2019/10/06
02:25:24
System up. 
2019/10/06
02:25:45
System shutdown. 
2019/10/06
02:29:47
HDD2 Hard Drive Has Failed 
2019/10/06
02:29:50
HDD1 Hard Drive Has Failed 
2019/10/06
02:29:53
admin login. 
2019/10/06
02:29:56
System up. 
Thank you