Removing HDD in one bay causes HDD in other bay to shut down

Has anyone come across this behaviour of my 5N

  1. starting the 5N using the power switch often crashes my iMac Pro into a black screen then a reboot. To prevent iMac from crashing, I now disconnect the thunderbolt cable and reconnect it only after 5N completes its boot up process.
  2. As I mentioned in my other post, erratically, each bay may suddenly decide there is no HDD in the bay. There is no set pattern which bay this may happen.
  3. Removing that HDD in the bay that is not recognising it, often cause a squeak sound in one of the other bay, and all HDD then gets disconnected, and 5 red light appear
  4. A software reboot often tells me only 1-2 HDD are recognised. They can be in any combination of HDD bay with no set pattern.
  5. Removing and re-inserting HDD interspaced with multiple reboots sometimes get the system to recognise all 4 HDD again. Then its the usual 12hr of data protection process.
  6. There’s even occasion that just putting the front cover back on cause a squeak sound in one of the bay, and all HDD then disconnect.
  7. I can always hear bay0,1 spin the HDD up and stay spinning, bay2 has never been able to recognise HDD and there is no spin up sound, bay 3 and 4 often spin the HDD up only to give a squeak and then the HDD goes quiet again.


  1. is this a sign the circuit board is dying
  2. can it be a sign the power adaptor needs a change?

A squeak sounds more like a drive or drives dying than any other cause.
They should never squeak, neither should the cooling fan, though you said it was the drives, in either case, squeakers need replacing.

Power adaptors have been known to be at the root of some strange & bizarre faults, including odd start-up behaviour, & since it’s the cheapest place to start, no harm replacing it to eliminate it as a cause.

My guess is you’ll be replacing drive(s) though, healthy drives do not squeak. Raising a support ticket could help identify which one(s) as they can often tell from the device logs.

I’d only start suspecting the board or corrupt firmware after both replacing the power adaptor and trying setting up the unit with a pair of known good (non SMR) drives instead of the existing drive pack… if it still misbehaves, it could be an internal problem with the unit itself.

Thanks for the reply and interest in my weird problem

  1. the drives are Toshiba N300 6TB NAS HDD bought in Dec2021
  2. I would think if one drive squeaks, that drive bay will go off, but
  3. the whole 5N goes off (hence I thought it was a power issue ie power cable or circuit board)
  4. just now, just by knocking the table the 5N was on, a squeak could be heard, and all 4HDD went offline

I’m now playing with the various removing, reinserting, rebooting routine to get all 4 up.
So far can get 1-3 HDD up in various random bays, not all the time having the same 1-3 HDD getting online though.

Will probably get a new power supply and then replace the HDD if the problem persist, and follow your advice to troubleshoot.
Thanks again

Drobo power supplies don’t have much spare capacity, if one drive pulls enough power even briefly it wouldn’t surprise me in the slightest if the unit reset completely, losing contact with multiple or all drives is no surprise either if the voltage dips.

I’d be inclined to connect the drives to a PC to read out the SMART data & see if I could learn anything from that.
I’d also avoid running the unit as much as possible until I’d got the problem identified, the last thing you need is for one drive to die & take data on another with it as collateral damage, in such an event it may be impossible for a rebuild to complete even with a new replacement.

Thanks for that info
It’s just that I can’t isolate with consistency the one HDD or HDDs that is always squeaking.

At the moment while I’m doing the remove, re-insert, reboot process to try to get all 4HDD up, sometimes bay0 HDD squeaks when bay1 HDD is removed, sometimes bay3 HDD squeaks when bay4 HDD is removed, the pattern is very random.
(I’m doing the remove, re-insert, reboot because Dashboard states no drive/insert drive in the bays even when drive is there, and all 5bay are red light, sometimes, some are constant red light, sometimes blinking red light)

I find it really hard to accept that all 4 HDDs are faulty, maybe 1 or 2 are faulty, but like I said, I can’t find that 1-2 HDD that squeak consistently.

I’m waiting for the new power adapter to arrive to see.
Failing which I really think the 5N has reached end of life.

Thanks for your advice. Much appreciated.

I’d be very wary of shuffling drives in & out whatever the reasoning, it’s entirely possible you’ll arrive at a state where suddenly your data can’t be accessed or rebuilt without resorting to expensive recovery labs, if even they can do it.

I strongly advise investigating the actual cause rather than shuffling & hoping, even if it means paying for support.

Thanks v much for the advice - it’s ok - 5N is my 4th backup - it was my starting journey for DAS - so I got a 2nd hand to try - it was all good for 3 months - then I decided to shut it down for a few weeks.
When I started it back - this was what happened.

I feel the HDD SATA connecting pins, sits in the Drobo SATA slots rather loosely.
I’ve taken the 5N apart and saw that compared to my other HDD enclosures, HDD in Drobo seems to be able to move more because of the shallow inserts. There’s also like a higher chance that sometimes when the HDD is inserted, it may not go all the way in.
Maybe this explains why sometimes the HDD is “accepted” by the Drobo SATA slots and sometimes not, depending on whether that “insert” creates a good contact or not.
May also explain why Drobo Dashboard states the Bay is Empty even though the HDD is in the bay.

Now that I have got all 4 HDD online again, it occured to me that every time I managed to get 4 HDD online, it was when the Drobo has been on and heated up for more than a day.
Maybe the heat kind of “expanded” some circuits so that the connections between HDD and Drobo becomes established.

I may not be making sense, but what the heck, I just take it as they come.
Will probably get a Terramaster or a QNAP DAS / NAS when the need arises.