KVM switch only half-working

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quickymart

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#310969 4-Dec-2023 10:39

I'm trying to get a KVM switch working with my setup, to allow me to switch one set of keyboard/mouse/monitor between a laptop and desktop machine.

I ordered one off Trademe (one of these: https://www.trademe.co.nz/a/marketplace/computers/cables-adaptors/other/listing/4446593920?rsqid=f2ea041bad174ee1acbc60ce41c5c2a4-001&bof=wQ7zKLt9 ).

It duly arrived and I connected everything up according to the instructions.

It switches between the displays absolutely fine but I can't get external peripherals (so far the mouse or a USB headset) to work - nor does the webcam built-in to the monitor.

One wireless mouse simply doesn't work and the older one has issues getting enough power from it (I think). It's a pity as the KVM is a really nice unit but I would just love to get it going.

Has anyone used these and can give some suggestions please?

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#3167897 4-Dec-2023 11:40

Sorry, can't answer your question, but I recently got one of these:

https://www.pbtech.co.nz/product/KVMATN0022/Aten-CS22U-Economy-2-port-KVM-switch-USB-VGA-Cable

And can confirm it does what it says on two Win10 machines for the keyboard and mouse. I don't use the VGA display switch - the monitors have dual inputs so I have to switch them separately

quickymart

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#3167988 4-Dec-2023 13:09

That looks good except I need something that has the following connectors:

HDMI X 2 (the one above doesn't appear to have HDMI on it)

Keyboard (PS/2 with USB adapter) X 1

Mouse (USB) X 1

USB headset X 1

Does such a KVM device exist?

Rickles

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#3168035 4-Dec-2023 16:08

Have you tried using a wired mouse and wired keyboard, just to test that it might be the wireless parts that are faulting?

richms

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#3168038 4-Dec-2023 16:17

When I have tried cheap KVMs they have totally failed with any composite devices like USB receivers that are both a mouse and keyboard and other things, and gaming mice and keyboards that enumerate multiple devices to allow for the mouse to have keyboard macros and the keyboard to have n key rollover and also to control the RGB.

Try it with the cheapest nastiest wired mouse that you would have bundled with a HP or Dell workstation and see how it goes.

Richard rich.ms

quickymart

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#3168044 4-Dec-2023 16:43

richms:

Try it with the cheapest nastiest wired mouse that you would have bundled with a HP or Dell workstation and see how it goes.

By pure coincidence, I had one of both so tested them and it all works (although the USB wired headset is still unconfirmed but I suspect it won't work). However, I don't want to use either this mouse or keyboard on a fulltime basis.

So does that mean this KVM is a dud? 😕

fearandloathing

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#3168045 4-Dec-2023 16:45

quickymart:
the older one has issues getting enough power from it (I think).

I suspect power is your issue, try adding the peripherals via a usb powered hub.

johno1234

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#3168046 4-Dec-2023 16:46

quickymart:

That looks good except I need something that has the following connectors:

HDMI X 2 (the one above doesn't appear to have HDMI on it)

Keyboard (PS/2 with USB adapter) X 1

Mouse (USB) X 1

USB headset X 1

Does such a KVM device exist?

PS/2 keyboard unlikely these days? I wanted HDMI but the options on PBTech were very expensive so gave up on that and just have to press the monitor button to select input. As you have seen, there's quite a few on TM but no bloody use if they don't work. I expect they will work in the simple case of wired USB separate keyboard and mice though.

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richms

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#3168054 4-Dec-2023 16:56

quickymart:

By pure coincidence, I had one of both so tested them and it all works (although the USB wired headset is still unconfirmed but I suspect it won't work). However, I don't want to use either this mouse or keyboard on a fulltime basis.

So does that mean this KVM is a dud? 😕

Working as intended, so not really a dud. If you want something that does full USB decode and will work with more devices look at the ones made by level 1 tech. LTT did a video about them and that made a friend get one and its the only one that has worked properly with nice gaming hardware and decent monitors on their cad workstation.

Not sure how USB audio would do on one of them I suspect it will not work at all. Generally the cheap switches will have a dedicated mouse, a dedicated keyboard and then a seperate USB port for all your other tat that you want switched between them.

I gave up with the K and M part and use my cheap one for video and got a USB switch with 4 USB 2 B ports, one USB 2 A port and 4 clacky buttons that passivly switch it and then put a powered hub on it. Its crude, manual, but still works for the off time to swap mouse and keyboard and stuff over to whatever ras-pi or whatever I am working on that I cant get SSH into. For video I got a HDMI matrix switch that I can use to put 6 sources onto 2 screens so have 2 of them to the workshop PC and the others for whatever I am working on and a chromecast. Again, pain in the A manual switching but at least it works.

Richard rich.ms

richms

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#3168055 4-Dec-2023 16:57

fearandloathing:
quickymart:

the older one has issues getting enough power from it (I think).

I suspect power is your issue, try adding the peripherals via a usb powered hub.

That will make it even less likly that the little microcontroller in the switch will be able to snoop on the communications and switch. I think some of them even need the device to be running at usb 1.1 super slow speeds to be able to observe the keypress to swap over.

Richard rich.ms

quickymart

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#3168077 4-Dec-2023 17:24

richms:

quickymart:

By pure coincidence, I had one of both so tested them and it all works (although the USB wired headset is still unconfirmed but I suspect it won't work). However, I don't want to use either this mouse or keyboard on a fulltime basis.

So does that mean this KVM is a dud? 😕

Working as intended, so not really a dud. If you want something that does full USB decode and will work with more devices look at the ones made by level 1 tech. LTT did a video about them and that made a friend get one and its the only one that has worked properly with nice gaming hardware and decent monitors on their cad workstation.

Not sure how USB audio would do on one of them I suspect it will not work at all. Generally the cheap switches will have a dedicated mouse, a dedicated keyboard and then a seperate USB port for all your other tat that you want switched between them.

I gave up with the K and M part and use my cheap one for video and got a USB switch with 4 USB 2 B ports, one USB 2 A port and 4 clacky buttons that passivly switch it and then put a powered hub on it. Its crude, manual, but still works for the off time to swap mouse and keyboard and stuff over to whatever ras-pi or whatever I am working on that I cant get SSH into. For video I got a HDMI matrix switch that I can use to put 6 sources onto 2 screens so have 2 of them to the workshop PC and the others for whatever I am working on and a chromecast. Again, pain in the A manual switching but at least it works.

Thanks for that, unfortunately with my desk setup a separate mouse/keyboard for each system isn't really viable - hence why I was seeking the KVM switch as a solution.

That's quite depressing, I would have thought something like this should just be plug and play and start working.

Note that my keyboard is cabled however I am currently waiting on the PS/2 to USB adapter to test it, so it may turn out to be fine. However if it does, this still wouldn't resolve the issue of the mouse or the headset not working with this switch.

With that in mind, can someone suggest a KVM that would work with my setup/requirements? Would a USB switch (as suggested above) make any difference here?

fe31nz

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#3168200 4-Dec-2023 23:59

Basically with KVM switches, it is getting what you pay for. The cheap ones are only moderately likely to work unless all your devices are very plain standard things. There is a reason the ones that work well cost quite a lot. So take a look at the more expensive models from companies that have a long history of making KVM switches, such as Aten or Rextron. There are other companies now who do make good ones too (I am using one from TESmart), but you need to understand what to look for.

The first clue to look for is that the advertising mentions it supports EDID - this is where the KVM switch copies the EDID data sent from the monitor to the PC that describes the monitor's capabilities. It then provides that EDID data to all computers on the KVM switch when requested, so that you can boot a computer without that computer being currently connected to the real monitor, and computers can then not tell if they are really connected to a monitor or not. Without this, you often get computers switching to a default screen mode (eg 640x480) when switched away from the real monitor, and this really messes up your desktop every time it happens.

Good USB support will have separate USB ports for monitored keyboard and mouse support, and at least one more unmonitored USB port. It is best if there are two unmonitored USB ports so that in the worst case you can have your mouse and keyboard both unmonitored and use the buttons on the KVM to do the switching. Then it does not matter if your mouse or keyboard is compatible with what the KVM switch understands. My TESmart KVM does not properly understand my ancient Microsoft Comfort Optical Mouse 3000 or my equally ancient Microsoft Internet Keyboard Pro, so I have them connected via the unmonitored ports. It comes with an infrared remote control that I have on my desk beside the keyboard where I can easily use it to change between my four PCs. The IR receiver is set up just in front of the remote so it gets 100% reception.

askelon

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#3168235 5-Dec-2023 08:33

i use an AIMOS 2 Port KVM myself. I just plug in the USB/HDMI into each computer and a USB wireless dongle into the USB ports on it for my keyboard and mouse and have never had a problem.

quickymart

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#3168451 5-Dec-2023 16:29

askelon:

i use an AIMOS 2 Port KVM myself. I just plug in the USB/HDMI into each computer and a USB wireless dongle into the USB ports on it for my keyboard and mouse and have never had a problem.

Are you able to provide a pic of your setup please so I can have a look and see if it would match my requirements (as listed above)? This might be what I'm looking for.

quickymart

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#3168559 5-Dec-2023 20:03

Forgot to add, my monitor has a built-in webcam connected via USB, so that would need to be supported as well.

askelon

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#3168590 6-Dec-2023 07:32

I literally just have a two PC's connected via PC1/PC2 on the back with my screen plugged into the Output. I cant remember if it came with cables or i had to buy them. On the front of it I have my wireless mouse/keyboard dongle plugged into the "mouse" usb port. I havent tried plugging anything into the other USB ports though but I guess they would work. Its currently all taped under a desk so its a little hard to take pictures of. I just use the main switch on the top of the unit to switch between the two - I normally have one set connected to a mini PC I use and the other set connected to whatever Im working on at the time. It is only USB2.0 but thats fine for basic peripherals like Im using. And it most definitely needs the USB cables plugged into a computer to power it.

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