Bizarre USB problem with new Mac Mini

[imac275]

I have just picked up a refurb Mac Mini and am using it with a Logitech K400 USB keyboard. It all works fine, until I connect an external HDD.

At that point the keyboard stops working, but it is fine again when I remove the HDD! I have tried varying the USB ports I am using for each, but it doesn't seem to be able to support both at once.

I don't really want to send it back to Apple if it is a 'feature' rather than a fault, but I have never seen anything like this before.

 

[shaunp]

I'd try a different keyboard (and USB HDD if you have a spare) before returning. See if one of the other components faulty first.

 

[Yahooligan]

Does the HDD have external power or is it powered by the USB port? If it's USB-powered then it could be drawing too much current and the USB controller ends up disabling the ports to save itself. However, that should result in a warning popping up on your display that there's too much power draw via USB.

Perhaps try connecting the drive to a powered USB hub and see if that helps. Also, some USB HDDs come with a Y-cable that has two USB connectors on one end, this is so that the drive gets sufficient power by using 2 USB ports (One for power only) as a single port may not supply enough power.

 

[imac275]

Yes, it is bus powered (WD Passport 2TB). I'll try a different one first.

 

[imac275]

I have now tried a mains powered external and it works fine, but is too loud, so I bought a powered hub and went back to the passport.

The strange thing is that the passport still will not co-exist with the keyboard.

If power is not the problem, I can't work out what is.

 

[jbarley]

is the hub you purchased a USB 3.0 hub?
If not, and your external drive is USB 3.0 then you could still be having an insufficient power issue.

 

[imac275]

I now seem to have solved this. Apparently, the keyboard is known not to work if it's wireless dongle is in close proximity to a USB3.0 device. Putting either the dongle or the HDD on the other end of a 1.5m USB extension lead solves the problem.

I am still unsure why the keyboard seemed to work fine when it's dongle was plugged in right next to a mains powered desktop USB3.0 HDD but not the Passport drive when it was plugged into a powered USB3.0 hub.