I have Asus N580VD laptop which has two USB 2.0 ports, one USB 3.0 port type A and one USB 3.1 port type C.

Yesterday I was tinkering with an Android phone, rebooting it in different modes. It was connected to the USB 3.0 port. Plugged it out and in from time to time. At the same time some Windows updates were installed in the background.

At one point I've noticed it stopped being recognized. Later I've noticed that USB 3.0 devices (I have a USB 3.0 flash drive) work just fine there. But no USB 2.0 devices are recognized. However, they are still powered, the port supplies power.

There's a similar question (USB 3.0 port no longer recognizing USB 2.0 devices, seems to still work with USB 3.0 devices), which describes the same situation, only my OS is Windows 10 x64.

There is an answer suggesting the port is physically damaged (namely, USB 2.0 pins). But a comment asserting that USB 3.0 negotiation takes place on USB 2.0 pins makes me wonder if it's really the case.

Can I somehow pinpoint the cause for the problem and fix it, if possible?

I have a flash drive with Live Ubuntu installation, and the port doesn't work for USB 2.0 devices there either. However, I can try to look at some Linux logs, if someone tells me where to look.

Maybe there are two chips for that port inside my laptop, one working with USB 3.0 devices and the second one working with USB 2.0 devices, and the latter is now burnt?

  • Even if USB 3.0 negotiation takes place on the USB 2.0 pins, there are two different root hubs for USB 3.0 and USB 2.0, so if the USB 2.0 root hub has been damaged for some reason, USB 2.0 won't work. So your last sentence is spot on. Please boot Ubuntu, plug in a USB 3.0 device, and edit question with output of lsusb -t (indent 4 spaces to keep the formatting). Then unplug it, plug in a USB 2.0 device, unplug that, upload output of dmesg somewhere, e.g. pastebin (redirect with dmesg > file_name), and edit question with link.
    – dirkt
    Apr 13, 2018 at 12:21
  • It seems that you are working in IT capacity. Don't you know configuration tools like Device Manager and USBTreeView, to see what is in the USB tree, and which driver is installed and which one is failing? Get the info and come back. Try to roll back your USB drivers as well. Check if mouse/keyboard/flash is working in BIOS/UEFI. Apr 16, 2018 at 0:33
  • Do other USB2 ports work, or only your USB3 fails for USB2 devices? Does a USB mouse work in any port? Apr 16, 2018 at 0:36
  • As I understand USB 3.x negotiation the USB 2.0 data wires are not required for operation, I recall the USB 2.0 data wires can used as a fallback if negotiation on the "super speed" data wires fails. It is plausible for the USB 2.0 function to be damaged and not impact USB 3.x function. There is not likely an easy fix or workaround for this.
    – MacGuffin
    Aug 1 at 12:02


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