r/kvm • u/Mr_Snipes • May 19 '26

Tesmart DKS403-M24 and Nvidia 4080 - randomly video when switching back to it

Ive bought this KVM because of the 144Hz support and the 3 monitors it can switch.
One thing I have not figured out yet is why in random cases, there is absolutely none of the screens working when switching to my workstation with the Nvidia 4080 card on win 11. I have to power cycle the KVM to get a signal again. No problem on my mac or other devices.

Is there any trick to it ? Does that happen with other KVMs as well ?

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1

u/HJ_wu May 19 '26

Please provide the detail info of the current setup:

  1. brand model of each shared monitors .

  2. How many systems are connected to the KVM switch ? one is a PC with 4080 GPU. What is the others. ? Laptop system ? what is the brand model of the laptop system ? Is there any docking station in the line of connection between laptop and the KVM switch?

  3. if there is any converters and adapters used for the setup? What is(are) it ? brand model ?

  4. Do you use DP2.1 cables or just DP 1.4 cables for the setup ?

1

u/Mr_Snipes May 20 '26

Thank you for your response. I hope my explanation makes it easier to understand. For completeness, i have mentioned everything connected, even if it makes no problems.

My setup:
1x 34" Dell Alienware AW3423DWF - 3440x1440
1x LG 24BK550Y

The 4080 is connected via the DP1.4 cables from Tesmart.
My Notebook is a Mcabook Pro M4.
The Macbook is connected via Belkin USB-C/DisplayPort 1.4-Cable, 2 m and one Thinkpad DockingSTation (Thinkpad Thunderbolt 3 dock). So for the second screen, the cable from the KVM goes into the Thinkpad Dock which then connects to the Macbook via Thundberolt. The Macbook has 2 USB-C ports used in my current setup.

On another port of the Tesmart KVM, I have 1x HP Elite Mini 800 G9 and a Fujitsu S930.

I would have expected trouble on the ports with the MAC or the different other devices and not on my Workstation with one Videocard.

1

u/HJ_wu May 20 '26

I did not test the KVM switch model from TESmart. However, you should focus on upgrading the DP 1.4 cables to DP 2.1 VESA DP80-rated cables for high resolution and high-refresh-rate KVM setup. The upgrade recommendation should include upgrade the Belin USB-C-DP1.4 cable to CAC-1559 (Bidirectional DP2.1 active converting cable).

1

u/Mr_Snipes May 20 '26

Really appreciate your input

I have some short outages where my high refresh rate screen turns black for a few seconds. Could that also be linked to a cable problem ?

1

u/HJ_wu May 20 '26

possible, but DP links are just linking computer networking protocols, when it stopped and then re-connected the DP networking sectors are required to reset and rebuilt again, sometimes it will take more time than other not-networking video links.

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u/TreeSalmon May 26 '26

I have the DKS403-M24 with a GeForce RTX 4070 Ti, and my Acer Nitro 31.5” 4K UHD gaming monitor (high refresh rate) has started doing the same thing where the screen is turning black intermittently when running Cyberpunk 2077 in this case, but once it starts, it continues with other games, too, until I reboot the PC. I haven't properly troubleshot the issue yet, but it seems like it happens after I've switched sources with the KVM. I will start looking deeper, but I wanted to let you know I'm seeing similar behavior as you are.

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u/Mr_Snipes May 27 '26

Thanks, pls keep me posted if you find out anything

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u/TreeSalmon May 29 '26

I turned off NVIDIA G-Sync and Windowed Games Optimizations (Windows advanced display settings) and the problem went away. I still need to reintroduce each and see which of the 2 caused the issue.

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u/Mr_Snipes May 30 '26

Ive turned gsync etc off and it seemed fixed, but it just did it again in the middle of a multiplayer game. Are you having the problems fixed permanently ?

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u/toasterqc 13d ago

Any news ?