Author: sawbona Date: To: Gregory Nowak via Dng Subject: Re: [DNG] OT, USB device error -71
On 26 Oct 2023 at 21:57, Gregory Nowak via Dng wrote:
> ...single on-board USB 3.1 port on the IO panel, it throws a bunch
> of USB -71 errors ...
> ... a regular bus powered USB 3.0 hub between the broadband device
> and the laptop, win10 picked it up with no problem.
---
usb 3-2: device descriptor read/64, error -71
usb3-port2: unable to enumerate USB deviceusb usb3-port2: attempt
power cycle
---
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.
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.
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.
You don't say if it uses a cable or if it plugs in directly.
Below spec OEM cables is the most common source for this type of
problems due to voltage drop.
If so, see if you can find a shorter, better quality cable to try it
out to see what happens.