Hmm, I kind find the specifications for that anywhere. Does the side of the box say the number of amps and volts that it can support?
Nothing on the hub itself but the old AC adapter says 5V * 3.5A = 17.5W.
Perhaps the BEs were drawing more power than the AC adapter was rated for, for too long.
This is the best explanation I can come up with, but it really doesn't explain everything going on here. It really seems like the BEs are using a lot more power this last week for some reason.
Since I dropped the number of BEs to 10x 5 hours ago they've been hashing flawlessly (0.5% HW error) with the desktop PSU powering the hubs. The PSU is at least 350W so I can't understand how 12x BEs are too much for it.