Question Anyone Seen This One... Deader Than Dead

Feb 1, 2022
Hi everyone!
I've been around computers for decades, worked at IBM 15 years, built many computers over this time, and I have NEVER seen this...
The system in question, one I built some years ago:
MSI Z97 Gaming 7 motherboard
8GB Corsair memory
Kingston 500MB SSD with Windows 10 installed
2 x 2TB Seagate SATA hdds

The other day I go to power it on and it basically said "no soup for you". The system started up and then powered off within a second, then started itself back again, and a second later, powered down, rinse and repeat.
I happened to have a new, never used power supply so I removed the old one, cabled up the new one and it did stay powered on. Good news I thought... Until no OS booted.
And even worse, none of the 3 hdds were seen by the BIOS. It was if they weren't there.
I have 3 other computers and I attached each of the hdds (one at a time) and in each case the hdds may as well be another brick in the wall - I would've gotten the same results.

So, any ideas what may have caused a previously good 3 hdds to be wiped out to such an extreme? Virus? Hacked? The absolute worst luck in HDD history?
The motherboard still boots to the UEFI/BIOS and if I attach a different hdd (one that was laying around collecting dust) it sees it. Even with the original SATA/power cables...

Power supplies after they get so old (or poorly build ones) can fail and put a power spike through your system damaging critical system components. That's why it's vitally important to buy a quality power supply in the first place that have multiple safety features to help prevent that from happening.