Hello, I’ve been having problems with the USB3 port on my Dell monitor for a few weeks now.
Every time I start Windows 10 I get the message: “USB device not recognized”. (see screenshot 01). No USB device is connected though.
The following entry then appears in Device Manager under the USB controller tab: “Unknown USB device (linked in compatibility mode)”. (see screenshot 02)

The problem stems from the monitor’s USB3 port 4, at the top of the USB port as seen in the USB tree view. (see screenshot 03)
A special feature of the port is that it has a “BC1.2 Charging Connection” function, so it can deliver a higher voltage than a normal USB3 port. (see page 11 Monitor Manual)

If the message appears when Windows 10 starts then no USB stick or external hard drive is detected on port 4. However power is supplied, the LEDs light up on the various USB sticks.
Oddly enough, smartphones with a USB cable are still fully recognized, and in addition to charging, data transfer is also possible here.

I then connected the monitor to my notebook and to its USB3 port. The same message appears here when starting Windows 10 with A300.

I’ve already tried a lot and don’t really know what else to do. Many would now probably say that this is a hardware defect. However, the said USB port 4 works without any problems, as I describe in the following section.
It seems to me that somewhere an incompatibility has kicked in, causing the primary USB port to be seen as a charging port instead of just a port for data transmission.
This is only happening for about 7-8 weeks (USB port didn’t work) and error message is showing when Windows 10 starts for about 3-4 weeks. Unfortunately, I don’t have time to get more involved because of the various projects going on to tackle the problem.

data system

Monitor Dell P2418D
USB3 Port: Rear 2x, Side 1x + 1x USB3.0 BC1.2 . with
Information about the monitor: Dell 24 Monitor: P2418D
operation manual

What I’ve tried so far with no improvement:

• windows 10 fresh installation
• Start perfectly without connected USB devices
• Removed all USB devices with USBDeview
• Uninstalled all USB hubs and AMD host controllers in Device Manager and installed the latest chipset drivers from AMD.
• In Safe Mode, in Device Manager, uninstalled all USB Hubs and AMD Host Controllers and installed the latest chipset drivers from AMD.
• Another USB3 Upstream Cable from Monitor to DeskMini
• Try the rear USB3 port on the Deskmini instead of the front USB3 port
• Disabled the “Allow the computer to turn off this device to save power” option in Device Manager for all USB controllers.
• bios reset A300
• Monitor connection to notebook
• blow into the port with compressed air spray

Which gets USB port 4 from Windows 10 and the Device Manager entry to work normally without any error messages.

I found these methods after all trial and error. USB port 4 then works without any problems, USB sticks etc are recognized immediately and data transfer is possible without any problems, like it should be with USB ports.

A300 Deskmini (AMD Chipset)

• In Device Manager: Uninstall “Unknown USB Device” and also require: AMD USB Extensible Host Controller, then restart the system.
• In UsbTreeView: USB port 4 and select “Restart USB port”

Although these methods survive a system restart, after some start from standby or after the A300 is completely turned off, the message appears again in Windows 10.

other ways:

• USB stick in port 4 when booting the system, no error message and the port doesn’t work normally.
• Connect the USB cable to the monitor on the Deskmini USB2 port. Port 4 works normally, so far without any error messages, for example from standby.

Notebook (with Intel chipset)
– In Device Manager: Uninstall “Unknown USB Device”.

In the case of notebooks with Intel chipsets, this is enough for port 4 to work normally again. The Intel USB Extensible Host Controller does not require a reboot and uninstallation, as is the case with the A300.

At the moment I don’t know what else to try to solve the problem. Maybe someone here has some good ideas. Thank you for that.