USB hubs malfunctioning after power surge
February 14th, 2007 by jqrI, like many other people, have a bunch of USB hardware hanging off a hub. It’s a powered hub, but one that can run without external power if you are running low current drawing devices. Since I’m on a laptop setup, this is great as it’s one less power adapter to plug in unless I really need it.
Unfortunately I do need it when plugging in my $9-from-MSY 2.5″ hard disk cradle which I use for my backup hard drive. It draws too much current and needs the AC adapter on the hub plugged in. In fact this is the only way it works (it won’t even run off the laptop’s USB power).
Anyway this is manageable until I connect the hard drive having forgotten to plug in the hub to the mains (or the mains power gets disconnected etc etc). Windows immediately gives me this:
Which is fine of course but the rest of the hub has been blocked off as well killing my USB mouse etc. This is where the problem is - disconnecting and reconnecting the hub doesn’t solve the problem - it appears the device driver ‘remembers’ this device is causing a power surge. The popular misbehaving device trick of disable/re-enable also lets me down.
The dirty solution is to restart the PC. The quick and dirty solution is to go to Device Manager, View -> Devices by Connection, find the USB controller that is the parent of the misbehaved hub, and disable/re-enable it:
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