I have a USB-A 3.0 hub with ten ports. I've owned it for about 2 years now without any issues, until recently. About a couple of months ago I had a flash drive plugged into one of the ports on the hub and noticed it seemed to die much earlier than I had expected. Thankfully the data I lost I could get back, but it really concerned me when another flash drive in the same port died again a month after. These aren't cheap flash drives, either, they're really nice Kingston ones. They both visually appear to have the same controller, so my initial thought was that it's just a matter of cheap controllers. The flash drives were also plugged in and powered on 24/7, so I thought maybe that had something to do with it.
But then I decided on measuring the voltage output of the port to make sure it's not causing issues, and I discovered something interesting. The port where the 2 flash drives died is outputting about 5.48 volts. Curiously enough, the other two ports I checked output about 5.24 volts. I couldn't check all ten as the rest are occupied with other devices (all USB devices except my keyboard and mouse are storage devices, mostly HDDs but some flash drives).
My iMac outputs about 5.11 volts, a custom-built PC at about 5.08 volts and my Dell monitor at about 5.04 volts (it has USB ports, too).
My question is, how safe are all of these voltages, more particularly, the voltages from the hub? I use a lot of USB devices on my computers and using all ten ports on the hub would be very handy, but I don't want to risk damaging more drives if that's the case.
The most information I can find is "USB uses 5 volts," which doesn't help much here.
Update: I had a chance to disconnect all my drives from the hub. I reran the tests and found out that every port outputs a stable 5.42VDC (stable as in, the number didn't fluctuate for the 5 or so seconds it was connected). The wall adaptor should output 12VDC and outputs at the most 12.12VDC. No devices were connected at the same time during this measurement (update: with 7/10 I get the same results).
With that being said, is it still possible that this hub is usable? Could I potentially use a lower voltage adaptor to bring the voltage down to more acceptable levels? I ask because this hub I am using is really nice, and I'd hate to buy another one (I bought an Amazon basics one before and had problems with that). Of course, if it means risking my devices lifespans, I'll buy another hub.
I would like to note that the other devices on this hub, mostly WD My Passports (hub powered), one WD My Book (wall powered), a SATA Hitachi drive in a 3.5" Rosewill enclosure (wall powered), and a Crucial SSD in a Sabrent USB enclosure (hub powered) are all okay and have been plugged in longer than the flash drives that died were.