Trouble Shooting KVM USB Isssue

[jmh547]

I recently purchased a KVM (image below) for my home office.

I have three computers all running windows 10:
-HP Zbook - attached through HP docking station
-Old Toshiba Laptop
-Desktop (Extreme 3 Gen 3 w/ 2600k)

Both laptops work fine.

The desktop i keep having issues with the usb dropping. Sometimes it reconnects a second latter, other times I will see an error that the "USB device is not recognized" This typically requires me to crawl under my desk and move the usb on the computer to a different port. When the USB drops the video (HDMI) still works.

I am trying to figure out if this is a computer issue or KVM issue.

I have already tried:
-Uninstalling and reinstalling usb drivers
-swapping cables (issue seems to follow the computer)
-changing ports on the KVM (again seems to follow computer)

Any ideas on how to further diagnose or do I need to suck it up and buy a better KVM?

 

[infinitevalence]

is the PC extended, or plugged in directly to the KVM?

What OS are you running on the PC?

 

[jmh547]

PC is plugged directly into the KVM

All three computers are running windows 10.

 

[infinitevalence]

Search for your Power & Sleep settings, then click Additional Power Settings


From here click Change Plan Settings



Click on Change Advanced Power Settings


Make sure USB Selective Suspend is set to disabled, then hit ok/apply.


You may need to reboot, but this should keep it from suspending the USB ports when you KVM away from the PC.

 

[jmh547]

Search for your Power & Sleep settings, then click Additional Power Settings


From here click Change Plan Settings



Click on Change Advanced Power Settings


Make sure USB Selective Suspend is set to disabled, then hit ok/apply.


You may need to reboot, but this should keep it from suspending the USB ports when you KVM away from the PC.

I will double check when I get home but I think this is already disabled.

For clarity the disconnect doesn't just happen when i leave the computer. It will happen while modeling (Fusion 360), gaming, etc. The mouse and keyboard just stop working.

 

[infinitevalence]

It will happen while modeling (Fusion 360), gaming, etc. The mouse and keyboard just stop working.

Are you me?

In all seriousness I have the same issue but its across 2 PC's and both are extended 100ft via CAT6 and USB 2.0 extenders so im 99% sure its EMI related since I was cheap and did not run shielded cables.

Check the suspend settings first

Second, what motherboard? Is the BIOS up to date, because there was a AGESA bug that had USB dropout on some AMD chipsets for a while?

 

[don256us]

Items that I would look at are:

1) Already mentioned: How long is the USB cable to the desktop? Do you have an extension cable involved?
2) Which USB port(s) are you using? If you are using a front panel USB port (or similar) they have thier own USB circuitry. Sometimes this does not like to behave.
3) Are the USB port(s) on the desktop USB 3? The point of this question is that USB 3 ports tend to use a separate chip on the MB.

I would focus using a port that is native to the chipset of your board. This will remove any flaky chips outside of the CPU/Northbridge/Southbridge. Also, as mentioned, I would update all chipset drivers. Esp any related to USB.

Another thought is related to cable length. What devices are you plugging in on the KVM side? Possible power draw issue? Maybe the desktop port(s) aren't sending enough power for this configuration. Another reason to use a native port on the MB.

When working on desktops, I found that the USB ports bundled with the RJ45 port tend to be native ports that always work and I have better luck with those on any given desktop. I have no proof that my full theory is correct but when I setup a new machine, I always put the mouse and keyboard into those two USB ports. They tend to be USB 2.x but that is more than fast enough for a keyboard/mouse combo, is native to the CPU/chipset and tends to have full power and priority. YMMV

Good luck.

 

[jmh547]

Quick Update

• The USB selective suspend was enabled... I swear I checked this before. Regardless it is now disabled
• The USB cables i am using came with the KVM. They are strange HDMI cables with integrated usb (picture attached) not sure on the length but they are for sure <6ft. No extension cable involved.
• Desktop
  • Asrock Z68 Extreme 3 Gen3
  • I5-2500K
  • Mouse is razer basilisk x (wireless) (confirmed the issue is present with and with out the mouse running through the kvm)
  • Keyboard: Keychron K10 Pro in wired mode. (issue occure with two other keyboards as well)
• I have had the issue occur multiple times on the usb3.1 and usb2.0 that are on the rear panel of the mobo
• I did find the bios is out of date... i currently have P1.00 and Asrock just released (in 2012) version 2.3.

I will give it a day or two to see if the suspend fixed it. if not i will update the bios as a next step.

 

[infinitevalence]

Does that KVM have any settings/configuration tools such as USB emulation? My IOGear lets me turn off and off emulation via hot keys.

 

[unsafesteagle]

Are you pushing 5 volt power directly to the KVM?

If the KVM has an optional power adapter or micro-usb port please indicate when using 6' or longer cables.

 

[don256us]

Are you pushing 5 volt power directly to the KVM?

If the KVM has an optional power adapter or micro-usb port please indicate when using 6' or longer cables.

Yes! I see that it has a spot for 5V DC input. Maybe a micro USB connector. That would address my theories of this issue.

 

[jmh547]

I am pushing 5v through the micro usb power port. Cable is 4ft

There are no setting utilities for this KVM. It does not support any hot key switching.

after disabling the selective suspend I used it for ~1 hr with not issues last night. plan to try again tonight to see if it comes back.