:: Re: [DNG] OT, USB device error -71
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Autor: Gregory Nowak
Fecha:  
A: altoid via Dng
Asunto: Re: [DNG] OT, USB device error -71
Thanks for your input.


On Fri, Oct 27, 2023 at 04:19:50AM -0300, altoid via Dng wrote:
> On 26 Oct 2023 at 21:57, Gregory Nowak via Dng wrote:
>
> > ... a regular bus powered USB 3.0 hub between the broadband device
> > and the laptop, win10 picked it up with no problem.


> The fact that the device works properly with a powered USB hub and on
> another laptop indicates a problem related to the hardware not being
> able to supply enough power to the USB 3.1 device.


As I stated in my original post which you quoted, and which I left
above, this is a regular bus powered hub. The hub and all devices
connected to it draw power from the USB bus, the hub is not externally powered.

>
> If I recall correctly, USB2.0 requires 5V/500mA/2.5W and USB3.1
> requires 5V/900mA/4.5W.
>
> When plugged into a USB3.1 socket, the device asks for 5V/900mA/4.5W
> but the hardware cannot deliver, so it fails to enumerate.


This is the first time a USB3 device had a problem on two machines
with USB3 ports for me. Every other USB3 device I've used on the ports
on both machines has no problem. If this was a power draw issue, the
device should have refused to work on the USB2 port, where it works
just fine. Other USB3 devices also work fine on the laptop with USB2
ports at USB2 speeds.

>
> When plugged into a powered hub or a USB2.0 socket, the device asks
> for 5V/500mA/2.5W and both deliver with no problems, so it works.


No, please see my comments above.

>
> You don't say if it uses a cable or if it plugs in directly.


I forgot to mention that. It has a micro USB type b socket, like that
found on older android phones before USB c. I've tried two cables, one
long and
one short cables on both laptops and the desktop with the same
results. Both cables work just fine with other devices.

Greg


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