USB, Toshiba

[Duncan MacGregor]

Computer-built-in power supplies are often too weak to handle USB devices.


On Tuesday 18 January 2011 18:44:37 you wrote:
> This unit has own power supplier.
> 
> I will continue on the subject in about 12 hours.
> 
> zb.
> 
> On 19/01/11 01:16 AM, Duncan MacGregor wrote:
> > In my experience, some USB devices do not register unless they go through
> > a powered hub that has a power supply of well more than 1 amp. A USB
> > device can require 500mA, and some 2.5" drives require more than that.
> > 
> > If a USB device has insufficient power, it may register under  ' dmesg ',
> > but not be picked up otherwise. Connecting through a powered hub with,
> > say,  a 2.5amp power supply solves the problem.
> > 
> > 
> > Duncan
> > 
> > On Tuesday 18 January 2011 12:40:43 you wrote:
> >> On Tue, Jan 18, 2011 at 12:36 PM, Jason Shaw<grazer-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org>  wrote:
> >>> I would think that it should "just work" by mounting it.  Have you run
> >>> dmesg when you plug the drive in/power it on to see if Linux notices
> >>> something plugged in?  Take a look at /dev/ to see if there is
> >>> /dev/sd[bcdef]1, which should be one letter beyond your optical drive
> >>> (if you have one).  So, if your hard disk is sda, and optical drive is
> >>> sdb, then your external drive will most likely be sdc.
> >>> dmesg is your best starting point though as it will show you the device
> >>> name so that you can mount it manually.
> >>> -jason
> >> 
> >> Indeed, dmesg is important. I have an external drive that only seems
> >> to work through the super-short cable that came with it, but not
> >> through a longer cable or a hub, powered or otherwise. The power light
> >> comes on but it doesn't get recognized - I suppose the power is
> >> insufficient to actually make the drive go, blinkenlight
> >> notwithstanding.
> >> --
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-- 
Duncan MacGregor  -- Toronto --
--
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