DA1515+ Disk Crashed, But No Bad Sector

I have DS1515+ with Disk 3 Crashed but SMART Status Normal and No Bad Sector.

I changed the disk twice (first with RMA from WD, and second time with brand new NAS).

All have the same result (Disk Crashed ,Health Status Normal and No Bad Sector)

Could anyone help ?
Thank you in advance.

I would look closer at the detailed SMART data; what’s shown there on your screen shot is only a summary.

Disk 3 SMART Info

I am using Synology Hybrid Raid (SHR).

The disk in Disk 3 is a new disk.

I have replaced Disk 3 for two times (one with RMA from WD, and the second time I bought new WD Red Drive)

I was confused and I thought that the disk that I got RMA from WD was also faulty, so I bought another Disk and the problem is still the same.

This is the Volume of the RAID.

Maybe you’ll get more help on the Synology support forums? This is the support forum for WD Pro NAS …

Thanks for the advice.

I will try them.