Computer won't see USB connection

My machine has worked fine since assembly in Oct 2016. When I went out today to use my machine I had a message on my computer that said “A USB device connected to this computer is no longer working”. I restarted my computer and tried to connect with no success. I went and brought my MAC from inside and connected it as well as installing the recommended drivers and still had no success. (This MAC has always worked)
I took the controller apart and saw nothing that looked out of the ordinary except for the small fan to the outside being locked up. I know more than an average person when it comes to computers and their components so I know that would not keep it from working but heat damage could.
I am certain the power supply works because when I power it on I can hear the motors answer and turn on. Any assistance is greatly appreciated as I have jobs I need to get done this week if at all possible. Has anyone else seen this problem?


The latest version of MAC operating system has caused some hinky stuff for me, also. It won’t recognize my usb hub or my KVM switch. But I wouldn’t use a MAC for CNC anyway, for other reasons.

Yes sir. Evidently I could use some work in that area. Sorry to disturb you.

Are you going through a USB hub, or directly to the computer?

Directly connected to it with both the MAC and the Windows machine.

The Windows computer hadn’t rebooted since the last time I used it. Not sure if that always matters though.

When you go into Device Manager on the windows computer, under USB Root, Is one listed as “Unknown Device”?

I just bought the X-Carve and having this issue. They even sent me a new board and still no connectivity.
I’ve tried different cables, different main board, different computer, rebooting, reinstalling the drivers, NOTHING… Getting very frustrated

Yes Sir…I found that and tried to reinstall the drivers but it told me I still have the latest and greatest. Should I completely uninstall it and start over?

This issue can be caused if any of the following situations exist:

  • The currently loaded USB driver has become unstable or corrupt
  • Your PC requires an update for issues that may conflict with a USB external hard drive and Windows
  • Windows may be missing other important updates hardware or software issues
  • Your USB controllers may have become unstable or corrupt
  • Your external drive may be entering selective suspend
  • Your PC motherboard may need updated drivers

Which version of windows are you running?

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Windows 7

When I first put mine together the power supply was bad and I asked the same question. They told me there are fuses but not where I can change them.

Windows 7 is famous for USB issues, and, as you can see there are a lot of different things listed above that can cause this issue with a PC. From what you’ve said about your power supply, we’ll focus our attention around those remedies first. One of the things that makes PC’s more undependable than a Mac is that (with a PC) there are too many cooks in the kitchen, which can lead to this type of USB problem. First you’ll need to - unplug - your motherboard from the power supply. If your not familiar with this process then make sure you label everything BEFORE you start unplugging things. It might help to take a few pictures so that you can refer back to them when you reconnect the power supply.

Unfortunately turning your computer off with the power button just isn’t enough, because computers don’t actually turn off completely that way, and the motherboard will still be powered. You need to completely drain the motherboard from all power to fix USB issues. When you physically unplug the power supply from the motherboard the microprocessor on the motherboard will reload the drivers for you, and your USB ports should (hopefully) recognize all the devices again.

So first UNPLUG the PC from the wall outlet. Then unplug all the power supply connections from the motherboard. Again, take connection notes if you need to. Let it sit for around 5 minutes, and then plug everything back together. Once the motherboard is re-connected to the power supply, plug the PC back into the wall outlet. Let it boot back up. Wait around 10 minutes before testing it. If this doesn’t fix your issue then we’ll look closer at the drivers.

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I just reread your original post and saw this. Your power supply could be bad. Do you have another one to test with? Just because you can “hear the motors answer” doesn’t mean the power supply is fully functional. If it were me I would get another one just to rule it out completely as you diagnose it.

If you do not have a spare power supply you could get out a Volt Ohm Meter (DVOM) and test the one in question. the output is listed and if it is worn off there are usually diagrams online when you look. test every connection for proper output.

Excellent point Kenneth.

Barry if you post your power supplies make and model number I will do some research on it, and locate the paperwork for it so you can test it further.

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I still have the old one but of course it was DOA. I will look and see what model power supply I have and get back to you.

I can’t find my volt-meter (I have teenage children) so I can’t test it today. Hopefully I will get one I can use.

Had this problem yesterday with a wireless mouse. Laptop kept saying there was a problem with the USB device. I unplugged power, removed the battery. I then put battery back in and connected power cord and powered on the lapyop and everything was back to normal.

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I gave that a shot tonight. Mine too is a laptop so I did the same thing as you and I’m still getting no response from the controller.