Mbox 2 block other USB devices

[magentaS]

Hi there!

I have Mbox 2 sound card that I run on Windows 7. I was wondering why is it blocking other USB/midi device? I tried connecting my midi controller Allen & Heath K2, but when Mbox is plugged in, the K2 doesn't work. K2 only works when Mbox is not plugged in, and I need both of them so I could have my monitor speakers and midi control at the same time.
K2 has built in sound card, but I only want to use it as MIDI controller.
This happens even if mbox isn't default sound device.

Hope that I will get some kind of solution because I don't know how to solve this on my own.

Thank you in advance.

[albee1952]

It may be that the Mbox is using up all the available power from that USB bus. Usually, USB ports are in pairs, so try moving the K2 to another USB port, or try using a powered USB hub to feed the K2(assuming the K2 is also bus-powered)