[kwikbreaks]

What was happening with the earlier tech install Superhubs was that the "tech" was just swapping the modem for a hub and leaving the old modem psu in place. They were 10v instead of 12v and the power rating was lower than the correct psu.

There have been umpteen examples of whistling psus which were driving users potty.

I've no idea if the psu fell into either of those two categories or was just faulty but it got switched out for some reason - just hope that the reason wasn't "I must appear to do something and this is something".