Simultaneous Failure of All 4 Drives

Hello All –
I have an EX4100, appx 3 years old, which I use at home. We went on vacation for a week, so I shut down the NAS, unplugged it and gently put it in the home safe. Once home I reconnected the NAS and it indicates all 4 drives have failed. The front power button is non-responsive, and while I can connect to the NAS from my iMac, the dashboard only works if the drivers are recognized. I have two other drives in storage at work (I rotate them through) and everything is backed up into the cloud and onto an external hard drive. Tried a hard reset which didn’t work (no reset).
Given that the was neither a power surge or lightning strike to kill all four drives at once, I’m assuming the problem is with the NAS and not the drives.
Thoughts/suggestions?

Regards, Jack