XPS 8940, IOGEAR KVM, monitor not working

Since your 8940 has a discrete video card, you should always use the card’s hdmi or DP video port and not the integrated onboard hdmi.  I would test direct hdmi connection bth 8940 discrete HDMI and your Dell monitor first to verify good Windows video connection.  Use two high quality hdmi cables to test during this.

After that make sure you use the same two cables to connect 8940 to monitor w KVM as relay station.  If no signal, change 8940 to Inspiron but stay on same kvm channel and use same two cables.

1) Tested 8940 to Dell 3818 monitor with HDMI cable 1 connected to the onboard graphics card. Worked

2) Tested 8940 to Dell 3818 monitor with HDMI cable 2 connected to the onboard graphics card. Worked

3) Connected HDMI 1 from 8940 to KVM.

4) Connected HDMI 2 from KVM to 3818.

With #3 and #4 being to the graphic card itself, it shows the Dell logo and then when it goes into Windows, the monitor loses the signal and the screen goes dark.

With #3 and #4 being to the onboard HDMI, it shows the monitor never gets a signal and the screen remains dark.

The Inspiron works as expected with the KVM switch configuration without any problems.

Thanks for your thoughts and any additional insights.

Thanks much

Isn’t that firmware for the KVM itself and not a driver for the connected computers?  I have never installed IOGEAR software in any of the other devices.  This sounds interesting though.  Please enlighten me further. Thank you. 

@betterhealthguy - Did you install the KVM's driver on the XPS 8940? Be sure to read the yellow note at top of that page so you get the right one...

Sorry, it is a firmware update. So have you updated the firmware on your KVM?

how would you then solve that issue if the new XPS does not work with the KVM? What would be the suggested next step?  Thank you. 

Since your Inspiron laptop connected to KVM using same HDMI #1 and 2 cables work, but as soon as you switched the video source from laptop to XPS8940 desktop, you got temporary video (Dell logo, Windows logo) followed by black screen, it seems the most straightforward working diagnosis is this:

8940 desktop after it is powered up near the KVM emits EM interference signal that disrupts KVM operation.  That explains why KVM was still able to relay HDMI signal from pc to Dell monitor at the beginning few seconds after 8940 is powered up, but then quickly got cut off or blacked out by the 8940, which acts like an unwitting jamming device.  The desktop has much more power than the laptop.  HDMI cable is also notorious of being susceptible to extrinsic EM signal interference, particularly with too long cable.  Even without the KVM factor you are basically running a double length HDMI cable from 8940 to monitor.  So even if KVM still works, the EM interference from 8940 quickly jams the HDMI transmission through the double length HDMI cable, even though each cable by itself works fine connecting 8940 to monitor.

My device is from 2013 and it says the upgrade does not apply.  I may need to just get a new KVM to try but seems odd it works fine with my other devices.  

@betterhealthguy  - Some dummy questions:

1. Exactly which video card do you have?
2. Do monitor and KVM get powered on a few sec before you power PC on?
3. With KVM connected, what happens if you boot XPS 8940 and immediately start tapping F2 to open BIOS setup? Does monitor go black or...?
   
   
4. Assuming monitor doesn't go black in BIOS setup (#1), how is the Primary Display option set?
   
   
5. Assuming monitor doesn't go black in BIOS setup (#1), have you tried enabling the Multi-Display option in BIOS setup?  Don't change anything else, but save this change before you exit setup.
   If monitor goes black in BIOS setup, make this change with video card connected directly to monitor, no KVM. Then power off, connect via KVM, and boot normally...
   
   
6. What happens when you boot XPS 8940 in Safe Mode? You'd have to pre-configure Windows to boot in Safe Mode at the next boot when video card is connected directly to monitor. Then power off normally, reconnect KVM and then power on...

Thanks for your thoughts and guidance.  This led to new insights and I feel like we must be very close....

The graphics card is:
AMD(R) Radeon(TM) RX 5700 XT with 8GB GDDR6
Intel UHD 750

The monitor and KVM are both powered on and connecting fine to other devices.

I connected the 8940 to the KVM using the HDMI on the graphics card (as the onboard never showed even the Dell logo) and then powered it on tapping F2 as it booted. It did go into the BIOS and the screen remained connected to the monitor via the KVM.

Primary display is set to Auto. I tried setting it to AMD and restarting, but that did not help. I reverted it.

Multidisplay is enabled already.

Then, direct connected to the monitor, I set the next restart to be Safe Mode.

I then restarted and then changed the HDMI to the KVM HDMI and I DID for the first time, see the Windows login page (in safe mode).

Then we changed to add Network and selected Base Video. Still good through KVM.

Unchecked Base Video and restarted - still good through KVM.

I then took it back out of safe mode and the KVM then no longer will work. I see the Dell logo and then when it tries to go into Windows, it goes black and the monitor cannot find the HDMI connection.

So everything seems fine until it tries to go into Windows when not in safe mode.

Thoughts?

Thank YOU!

Hi Ron,

I don't see anything that falls into the categories that you describe.  

I attached an image of what is configured to startup.

Thanks for any additional thoughts. 

Thank you!

This sounded the same.  I tried the res at 1929x1080 but no change. 

https://www.reddit.com/r/radeon/comments/g2ihxj/display_issues_with_hdmi_kvm_and_amd_radeon_rx/

A bit of light at the end of the tunnel..!

Sounds like something loading during normal boot is causing the problem.  Boot the PC normally and open Task Manager and look on Startup tab to see what's loading at normal boot.

If you have an AMD control panel or other AMD app listed, disable it (them) at startup. Word of caution, if there's also an Intel Graphics app, do NOT disable both AMD and Intel at the same time. That way, if you run into problems you should still be able to connect monitor directly to the onboard Intel HDMI port and re-enable whatever AMD items you disabled and vice versa.  After you disable something, connect via KVM and boot normally to test.

You can also disable other non-essential items like Dell SupportAssist, Dell Update, Dell Mobile Connect, USB Type-C Status Display, etc. If you want to test effects of an anti-viral/anti-malware app that's loading at normal boot, disconnect your internet cable if you use Ethernet, or disable the WiFi card first, so you don't get hit by hackers randomly probing PCs on line when those aren't loaded. And remember to re-enable the "anti-" app(s) before allowing any internet connections...

And if disabling something doesn't solve the problem, don't forget to re-enable that app the very next time you go into Task Manager.

@betterhealthguy , it sounds like the issue is with your KVM.  It disrupts the signals higher than 1080p.  Your monitor probably has higher resolution than FHD.  When windows detects the monitor EDID signals, it sets to the highest native resolution which your KVM could not handle.  You can either customize your XPS display resolution to 1080p or set your monitor to FHD resolution or lower.