The raid mode is single.
Only HDD2 Slot works, and only HDD2 works even if the hard drive is moved.
If HDD slot 1 is broken, it should not work when the power is turned on, but the orange light comes on and sounds.
I am using the D2-310. I am using two 4T HDDs in single mode. But suddenly HDD1 Slot does not work. turn on the power for the first time, the orange light comes on and there is a sound, but it is not recognized. I replaced the hard drive and it works fine in HDD2 Slot. HDD2 Slot is working well, but...