MyCloud EX4 16T Raid5 - all 4 drives failed at once

I have a 5-6 year old EX4 16TB MyCloud that’s RAID5. It’s performed fine up until a couple of weeks go. We had a lightning storm and even though it was on a decent surge protector, I got drive errors on all 4 drives when I rebooted it a couple of days later. I think it was the storm that killed it.

It seems to boot normally - blue flickering power, then the drives startup one at a time and flicker for a few seconds. Next the drive lights slow flash for a second or so one at a time in sequence, then return to the quick flickering. After about two minutes the fan briefly runs, then I immediately get a red power led, the name shows up briefly on the display, then one at a time all the drive lights go red.

Cycling through the menu, it shows the cloud, Version 2.12.127, temp, fan speed, then Drive Status shows Fault, Capacity: 0MB Free, then Drive Failed in Bay 1,2,3,4. I find it difficult to believe all the drives failed at once. And my suspicion is that its the main board. I have not tried to access the drives separately outside of the MyCloud.

I guess my question is - could I by another empty EX4 drive bay (off ebay) and just load the drives into it? Would that work to get it back up and running? Without resetting the drives?

Or could I buy an EX4100 and do the same thing without having to rebuild all the drives? This was my backup solution and storage for some data where I don’t have a backup. I’d really like to get the 6-7TB of data I had on the MyCloud back if possible.

Any suggestions would be appreciated.


You may want to ask this in your sub-forum! Do you have OS3 or OS5?

I"m assuming it’s OS 3, I don’t recall ever updating the OS, the latest firmware for the EX4 was installed months ago. Is there a way to tell which OS is on it? Thanks


My Cloud EX4100 (

Thanks for the reply again. As I mentioned I’m not sure of the OS. I don’t ever recall the OS being mentioned anywhere, and aside from updating the firmware through the web control panel I don’t recall installing or updating an OS at all. I normally just logged in through the My Cloud website.

As I mentioned above the firmware was at Version 2.12.127. But as I’m reading more about this, it looks like it was way out of date.

I’ll ask on the OS3 sub-forum, I guess. My real question is, if the drives aren’t actually defective, would putting them in a new bay (either a used EX4 or maybe an EX4100) without wiping the data be an issue?