I followed the startup instructions here exactly: https://www.startech.com/faq/kvm-switches-setup
and Also the troubleshooting here: https://www.startech.com/faq/kvm_switches_general#SV211DPUA - by switching KVM and External cables, and performing the startup all over again, for example.
On my DESKTOP PC, which has a GTX 1070 with the latest drivers, and Windows 10 fully updated including the creator's update, this KVM switch always has issues which I will describe in more detail below. The Desktop PC has 2 HDMI-connected monitors which are NOT going through any KVM. They are always on. The KVM controls only one monitor via display port.
On my Suface Pro 4, it works every time (the 2nd PC connected to the KVM).
When I first turn on my Desktop PC, the KVM works fine. Then I switch to my surface, still works fine. Finally, I go back to my DESKTOP PC, and the HDMI-Connected screen (no KVM) begins to flicker on and off a few seconds at a time. The DP connected screen (through KVM) stays completely black, but the monitor light is blue (meaning it's not in idle). If I disconnect the DP cable from the DESKTOP PC, or turn the kvm-connected monitor OFF, the DESKTOP PC loads the 2nd HDMI-connected monitor without issue.
At this moment I have disconnected the display port cable from KVM-to-Desktop, but am still using the KVM to switch my controls (both mouse and keyboard) and use my other 2 remaining monitors on the desktop PC successfully.
I opened a chat w/ Startech, and they were actually quite helpful. Below are the further tests performed:
- Please connect the DP monitor directly into your Desktop as a third monitor (not passing through our KVM).
- ok completed. Monitor is up. So right now, I have all 3 monitors working just fine. And I can move between my SP4 and Desktop using the KVM for controls only, works great actually.
- Now I simulated the KVM's display switch by disconnecting the DP cable from your desktop, waiting about 20 seconds, and then reconnecting it.
- The monitor came back instantly when i plugged it in again after ~20 sec.
- Started on the Desktop. Only the Displayport monitor was connected to the desktop at this time (disconnected the other 2 HDMI directly-connected monitors). DP was connected THROUGH the KVM. No issues here yet.
- After I switched to the SP4, it worked fine on the surface too.
- Then I switched bakc to the desktop, and I saw nothing on the screen (no connection basically, but it did seem like it was flashing a little bit, trying to do something).
- After a minute of that, I tried to disconnect the KVM, and connect ANY of the monitors directly again to my desktop PC, but none of them connected. HDMI or DP, didn't matter.
- Then I thought maybe it was due to mouse/keyboard being non responsive, so I connected them directly via usb to the desktop. They wouldn't even get powered. No red light on mouse, no caps lock on keyboard.
- So I had to shut the PC down manually, restart, and everything came back.
However, they conclude that it's not hardware related to the KVM as the switch is very simple (see below).
It is nothing more than a hardware switch. Although the USB connectivity can be more complex depending on the models, the actual display switching has no chipset or particular technology other than a physical cable switch. There is no software, drivers or associated technology that could be involved either. Furthermore, we also know that your KVM isn't defective since it works on other computers. The absolute only difference from our KVM's usage and an actual manual cable disconnection is the fact that the KVM keeps the cable's connection alive. When switching, the computer loses the monitor's information (identification information), but remains aware that a hardware connectivity is there. This, normally, doesn't cause any issue on the computer's side other than resolution changes and monitor re-arranging.
So finally, I'm asking about what on my software or hardware side on my Desktop PC could cause this issue and if anyone has more items to try or look into to fix it.