Technology Tales

Adventures & experiences in contemporary technology

Carrying out a hard reset of a home KVM switch

20th March 2017

During a recent upgrade from Linux Mint 18 to Linux Mint 18.1 on a secondary machine, I ran into bother with my Startech KVM (keyboard, video, mouse and audio sharing) switch. The PC failed to recognise the attachment of my keyboard and mouse so an internet search began.

Nothing promising came from it apart from resetting the KVM switch. In other words, the solution was to turn it off and back on again. That was something that I did try without success. What I had overlooked was that there USB connections to PC’s that fed the device with a certain amount of power and that was enough to keep it on.

Unplugging those USB cables as well as the power cable was needed to completely switch off the device. That provided the reset that I needed and all was well again. Otherwise, I would have been baffled enough to resort to buying a replacement KVM switch so the extra information avoided a purchase that could have cost in the region of £100. In other words, a little research had saved me money.

Comment:

  • Alistair says:

    Yes, this is the hassle you have to go through to reset a KVM where one of the PCs has confused the USB hub built into the switch. As you say, it’s because one/some of the attached hosts still provides a dribble of power.

    It would be really helpful if there were a reset function to resolve this, or an option to NOT power the KVM from the hosts. I have bought a cheap 8-way to try to figure out how it could be modified, and I think it will require removing many (probably 16) diodes that gather power from both USB *and* video connections. It’s a significant reverse-engineering exercise!

Add a Comment

Your email address will not be published. Required fields are marked *

Please be aware that comment moderation is enabled and may delay the appearance of your contribution.

  • All the views that you find expressed on here in postings and articles are mine alone and not those of any organisation with which I have any association, through work or otherwise. As regards editorial policy, whatever appears here is entirely of my own choice and not that of any other person or organisation.

  • Please note that everything you find here is copyrighted material. The content may be available to read without charge and without advertising but it is not to be reproduced without attribution. As it happens, a number of the images are sourced from stock libraries like iStockPhoto so they certainly are not for abstraction.

  • With regards to any comments left on the site, I expect them to be civil in tone of voice and reserve the right to reject any that are either inappropriate or irrelevant. Comment review is subject to automated processing as well as manual inspection but whatever is said is the sole responsibility of the individual contributor.