Sometimes Ubuntu doesn't connect to my external USB drive

Johnny Rosenberg gurus.knugum at
Fri Jul 29 16:11:08 UTC 2011

2011/7/15 NoOp <glgxg at>:
> On 07/14/2011 04:59 PM, Johnny Rosenberg wrote:
> ...
>> Jul 15 01:56:30 EasyNote-MX66 kernel: [56274.949093] usb 1-2: new high
>> speed USB device using ehci_hcd and address 89
>> Jul 15 01:56:30 EasyNote-MX66 kernel: [56275.052409] hub 1-0:1.0:
>> unable to enumerate USB device on port 2
>> So it seems like it's at least trying, but failing for some reason…
> ...
> After a little googling, most of the 'unable to enumerate' errors seem
> to come from hardware issues (low power/dirty usb ports). Just for the
> heck of it, can you move it to another usb port, preferably a back usb
> port if it is on a desktop?

It's a laptop. It doesn't matter which USB port I use.

> Reason for asking is that usb ports on the
> front of a desktop typically are wired extensions of the motherboard usb
> ports (the ones that are connected to the back) & can pick up rf
> interference and experience low power. Might also be a faulty cable.

Checked with different cables.

> You could check the power:
> Also, in one bug report several users seemed to resolve by cleaning the
> usb contacts. Shot in the dark, but worth trying.
> Other possibilities:
> 1. Is your bios up to date? Older versions of bios may have difficulty
> with newer high speed usb 2.0 devices.

I just visited their home page and I couldn't even find my laptop
there (I found a lot of other ones though), so I don't know if there
is an update somewhere…

> 2. If you think you can rule out hardware/cables/power/RFinterference,
> then you might try backing down to an older kernel, or trying a newer
> kernel to see if there is any change. Also try searching:
> <>

Thanks for all tips and advice.

In this case the problem seems to be something else though: I have a
printer (HP Color Laserjet CM1312 MFP) and I use it with two computers
using a USB switch (two computers to one USB device). It's a passive
switch and there are two push buttons: On for connecting the printer
to my computer, and one for connecting it to my wife's. She has no
problems with it whatsoever, but when ”my” push button is pressed,
there seems to be some problems on most of the other USB ports, except
the one to which I connected my keyboard and mouse (I never use my
laptop's built in crap).

So I just pressed pressed the ”connect my wife's computer to the
printer” button instead and my external drive is now found without any
problems each time.

The strange thing is that when I connect the printer directly to the
USB port the problem does not occur, so I wonder how a passive switch
can cause problems like this…

Kind regards

Johnny Rosenberg

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