L1Techs 3 Monitor 2 PC KVM issues

Level1 Store KVM Helpdesk
1

Hello there,

I just bought a 3 monitor 2 PC (5 Gbit/s) KVM and having some issues with it.

My setup:

PC1: Windows
RTX 3090
3 DP to DP 1.4 Cables to the KVM

PC2: MacBook Pro 16’’ (2019)
3 USB-C to DP Cables connected to KVM

Monitors:
A: 1 21:9 2k 165Hz Monitor with FreeSync connected via DP to DP
B: 1 16:9 2k 144Hz Monitor with GSync connected via DP to DP
C: 1 16:9 FullHD 75Hz Monitor connected via DP to HDMI

Only Monitor A is working with both PCs.
Monitor B isn’t working with any PC. After powering the KVM off and turning it on again it now works for both PC. But I did that before already multiples times where it didn’t work.
Monitor C is working only with PC1.

I have tried switching cables and ports on the KVM with the same result for any combination.
All 3 USB-C to DP cables are working for Monitor A, but not for the other Monitors.

I also have the issue that sometimes when switched to PC1 my keyboard input is passed to PC2, every other USB device connected to the KVM is connected to PC1 only the keyboard isn’t.

Could the issue with Monitor C be related to cables even though they are all working for Monitor A?
Is the issue with Monitor B related to it having GSync and if so is there a way to get it working?

Kind regards,
Dracsos

2

Hi thank you for reaching out and welcome to the forum! Hopefully, we can get this settled.

MACs specifically do not like going USB-C → DisplayPort → HDMI

You might get a USB-C dock, this would probably help your compatibility. Or, is there another input on this monitor besides HDMI…?

Let’s take a look at your cables.

What are all your cables? Can you link them?

Is there any way you’ve hit the hotkey to force USB 3.2 (blue) ports to a particular port?
The hotkey to force this is:

L-Shift → L_Shift → U
^ it will force USB 3.2 to whatever PC is active when the hotkey is used.

The hotkey to disable this is:

L_Shift → L_Shift → F4

Once disabled you should hear two beeps meaning the force USB mode has been turned off.

3

Hi, thank you for your response

I have tried a USB-C dock with a DP port and connected it to the KVM. The monitor is now working without any issues. Thanks for the information, I didn’t know about that.

It is possible that I hit that hotkey on accident, but the keyboard isn’t plugged into any of the USB 3.2 ports, but into the USB 2 ports labeled with HID.

Since Monitor B is working I have not seen this happen again. But I did not switch as much between PCs as I did yesterday while testing things out.