Comet Remote KVM - No HDMI signal detected

y Remote KVM Comet has been updated to V1.3.1 release 2. I am receiving a message of "No HDMI signal detected".The device being controlled has only Display Ports. I am using a HDMI to DisplayPort cable. I have performed the following troubleshooting activities.

  1. Restarted the KVM
  2. Tested the Display Port on the controlled device and it does work, displaying to an external monitor.
  3. Reseated the cables multiple times.

I have just now tested HDMI(Comet) to HDMI (Windows controlled device) and that works.
I then just tested my DisplayPort on one end and HDMI on the other end, cable, to another controlled device(Windows) and that works.
The last test was to run a DP to DP cable from my controlled device (xcp-ng server ) to a monitor directly and it outputs just fine.
The problem for sure is the Comet. I have cycled through all the available resolutions presented and none work

I am seeing the following under /var/log/kvmd.log


2025-07-13 13:14:11,754 - kvmd.apps.kvmd.streamer - INFO - => -- ERROR [226.968  tid=1900] -- get 6911c resolution failed,use 1080P as default
2025-07-13 13:14:11,757 - kvmd.apps.kvmd.streamer - INFO - => -- ERROR [226.968  tid=1900] -- init rv1126 encoder failed

The log file is also getting spammed pretty hard with the following messages


2025-07-13 23:59:50,048 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,153 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,256 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,360 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,464 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,568 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,672 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)
2025-07-13 23:59:50,777 - kvmd.plugins.hid.otg.device - DEBUG - HID-mouse is busy/unplugged (write select)

I'm posting a similar problem in another thread but saw yours and am curious if you have looked into creating a custom EDID for your monitor?

My current setup, after the same kind of troubleshooting you're doing, is use of a DP splitter - DP > DP + HDMI. DP passes through. The problem is that there is no CDID setting in the app that matches. The instructions to create a custom EDID are just not clear enough for me to understand. Maybe you've had luck?

Just curious what you're finding.

you need a Display Port to HDMI cable. The comet need a HD_IN signal , It's HDMI/DP OUT for the controlled device

I am using this one from Amazon. This cable works fine as i tested it already.

OK, got it. Could you pls share your log file to me? And before that pls connect your DP to hdmi cable between the comet and your controlled device.

glkvm_device_log.zip (36.4 KB)

Here are the log files as requested.

HDMI chip can't recognized any signal .Because you said that HDMI to HDMI is okay. Then I just can't figure out what the problem is

Is the Comet rated to work with Display Ports (using a converter or a DP to HDMI cable) ?

We test the Displayport to HDMI Converter like this. didn't test the cable. Will buy and test this amazon cable.

I'm having similar issues.

've upgraded my KVM to v. 1.3.1 and connecting it my legacy Dell Inspiron 6400 laptop running Linux Mint LMDE 6. I am using a VGA to HDMI adapter to connect the video for the KVM. With 1.3.0, I had no issues with the video signal, but after upgrading, I can see the login screen, but after login, I get the No HDMI signal detected. I have checked my HDMI cable and attempted mutliple custom EDIDs but continue not to get a video signal. I can move the mouse and type on the keyboard on the host machine through the KVM.

Not sure what I should do next, Suggestions?

My apologies - I should have checked again. I have a 2nd Comet that was not updated (v. 1.3.0). No video signal is working on it either. It's a Linux Mint issue, not a KVM issue. I'm guessing that I don't have an EDID that Linux Mint recognizes.

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Update: I purchased this adapter as another test, along with a new HDMI cable. Comet still doesnt see any signal.

I am also attaching another round of logs for review
glkvm_device_log.zip (35.4 KB)

maybe you can export log to us .And we can see what the problem is

I do some reserch about DP to HDMI adapter. there's active/passtive adapter. the active one will get a better compatibility. I just don't which one you've got.
And I saw the active adapter will support higher resolution. So I wonder if you can change the resolution of your DP out to 1920x1080 for test?
The log seems no issue. we orderd the amazon basis cable, and will take about 1-2 weeks to get them for further research

If your Comet Remote KVM shows "No HDMI signal detected," try these steps:

  • Check HDMI cable and port connection
  • Ensure the source device is powered on and set to output via HDMI
  • Try a different HDMI cable or port
  • Reboot both KVM and source device

This often resolves signal detection issues.

I set it to this resolution in the app.

@alex_zheng I tried yet another DP_HDMI adapter and now its working!!

From my understanding, the cables can be active or passive but the adapters are not.