Zebra server was knocked offline by a power failure.
Power surge did take a victim as well – server’s power supply, a custom Dell OEM Lite-On model* got it’s standby circuit fried. It now only reads 2.5v (instead of 5v) when connected to mainboard. PSU does turn on without load but not with a mainboard connected. Sad. This was a good PSU, well made and very silent.
Well, at least the rest of the hardware seems intact.
I’ve temporarily installed an old 230W Hipro from an IBM Thinkcentre as a replacement. Won’t use it as a permanent replacement though, because the fan is way too loud.

Will have to go emergency PSU shopping.

EDIT: August 31st, 2018. One of servers hard drives started going south. It’s not the root FS drive, but since most of my servers 12 HDDs are of comparable age (except maybe for an 250 GB 3.5″ Samsung which is much older than the others) I have decided to get a cheap PCI-E x2 M.2 SSD and move my Linux root FS out of magnetic storage.

As for the new PSU, I’ve bought an 430W Seasonic S12II. It’s rating is overkill for my needs, but it’s dead silent, well built and has enough plugs to power my 8 SATA drives (other 4 HDDs are connected via USB. 2 internal and 2 external) without the need of any cable splitters or wiring mods.

* – my server is not a Dell, only the PSU was.