SEAGATE NAS BLACKARMOR 440 power problem?

Often freezes and one day does not turn on again or turns off immediately after, what to do?

Symptoms:

My NAS freezes from time to time, then increasingly often. Until the day when one of them died on its own. I press the "ON" button then I see the lights come on and hear it come on but go out immediately.
 I do several times, I leave it unplugged completely, I turn it back on, but turns off after a few seconds.
So, I try without the hard drives, it turns on and stays on.
 So, I put 1 hard drive back in and it also turned on. Test with a second disc, also lights up. On the third disc it turned off after 2 seconds. So, I concluded that after 12 years (bought in 2009) the PSU has seen enough ;)

Not sure if this fixes your problems there are too many possibilities to be sure but after 10-12 years these are things that can happen and like my BlackArmor turned on removing two discs drives (which I unplugged immediately afterwards) I realized that it was maybe a power supply problem.
To keep my 12TB (4x3TB) and my 16TB (4x4TB), it was not too expensive to try it.
So, you must find the right model and replace it, I have two identical NAS, so I bought 2 AC DC power cord, and everything has been working perfectly since.

It is essential to look for a power supply with the same voltage and amperage details as the original as well as the socket which must be identical. I did a search with the following phrase "AC DC BlackArmor 440" and found it easily.

But I don't guarantee at any time that this is the problem you're having, but it's a possibility worth checking by doing some basic tests to determine if the expense is worth the effort :)

Seagate BlackArmor 440 using RAID 5
Model 1 : HD232 ASSY HOUSING - STAR401
Model 2: ST320005SHA10G-RK
(They are identical even if the model's name differs.)
P/N: 60.61U07.003