XPS 7390 USB C monitors

​This issue has perplexed a few people, so I'm just asking here to get more opinions or possibly a resolution.​

​The issue is that the single USB C cable connection from my (XPS 7390 & Lenovo Ideapad 5 14) laptop(s) no longer produces video on (any of) my monitor(s) using (any of) my video capable USB C cable(s).​

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​I'll start off with the hardware I have (or had) available.​

​Laptops​​:​

​A) Dell XPS 13 9350​

​B) Dell XPS 7390 2-in-1​

​C) Dell XPS 7390 2-in-1 (Replacement)​

​D) Lenovo Ideapad 5 14 (USB C Spec says: "​​USB-C Gen 1 (power delivery & display port)​​")​

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​Monitors​​:​

​E) Generic USB C portable monitor YTH1330 is the only identifier I can find on this.​

​F) Dell P2219HC USB C monitor​

​G) Dell P2219H monitor​

​Cables​​:​

​H) USB C Cable (​​JYDMIX USB C to USB C 3.1 Gen 2 Cable (3ft/1M) 10 Gbps 5A 100W Power Delivery Fast Charging with E-Marker, Display Port 1.2 4K@60Hz video output)​

​I) USB C Cable (Generic, came with E) Writing on side: USB 3.1 Cable E340033 AWM 20276 80*c 30V VW-1 XLY​

​J) HDMI, DisplayPort etc cables.​

​Other​

​K) Dell WD19 USB C Docking station​

​L) USB C dongle with HDMI connection.​

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​2019:​

​A) Dell XPS 13 9350 ​​connects to ​​E) Generic USB C portable monitor​​ using one single USB C cable. This provides power and video using the one single cable. Excellent!​

​January 2020:​

​Received ​​B) Dell XPS 7390 2-in-1 ​​and connected it to a my ​​F) Dell P2219HC USB C​​ monitor using ​​I) USB C Cable. ​​This worked perfectly, Excellent, my desk is clutter free and only have to connect one single cable to my laptop which provides power and video and usb ports on the monitor! I also tested ​​E) Generic USB C portable monitor​​ with my new laptop and this worked perfectly too, using one USB C cable.​

​March 2020:​

​There was an issue with the laptop when idle for x minutes, the screen turned off and I had to hard reboot the laptop to get back to Windows (I think this was a Citrix issue, can't be sure but it only happened when I was connected to Citrix Workspace) This happened a few times over the last couple of months, not ideal, but worked okay once I rebooted.​

​However one time I was forced to reboot and from then on the laptop would not work with the monitor through USB C.​

​Over the next few weeks:​

​I raised a support query with Dell. They advised me to download all the latest drivers, update the bios etc, which I did, and after that didn't fix the situation, they did a remote control of my laptop and tried to fix the issue, but they couldn't. So they organised a technician visit. He came and replaced the system board on the laptop and re-installed Windows. While he was there, he checked ​​E) Generic USB C portable monitor ​​using his own laptop (previous gen XPS 13) and it worked perfectly using ​​I) USB C Cable​​. I borrowed ​​K) Dell WD19 ​​from work so I can use my multiple monitor setup. ​

​May 2020:​

​Dell sent me ​​C) Dell XPS 7390 2-in-1 (Replacement)​​. This also does not work using the single USB Cable, tested on both of my monitors. ​

​When tested on ​​F) Dell P2219HC ​​the single cable provides power to my laptop, it also has access to the USB ports in the monitor (wireless mouse, usb speakers connected) however there is no video.​

​When tested on ​​E) Generic USB C portable monitor​​, the laptop powers the display but the display shows "No signal). In Windows I can hear the "Device connected" ding sound when I connect the cable, but its is as if it's not detected as an external monitor. ​

​What does work​​:​

​1. E) Generic USB C portable monitor ​​or ​​F) Dell P2219HC​​ connected to Dell XPS 9350 using a single USB C cable.​

​2. Connecting the USB C cable to (any) laptop AND connecting a HDMI cable also (directly to Lenovo laptop, with dongle for XPS laptops).​

​3. (Current setup) connect ​​K) Dell WD19 to B) Dell XPS 7390 2-in-1 ​​using usb c cable. WD19 is connected to P2219HC via DisplayPort cable. P2219HC is connected to P2219H using Display Port cable.​

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​TLDR; ​

​Video used to work on my XPS 13 7390 (2019) using one USB C cable, but stopped working one day and I cannot get it to work again despite (replacing and) confirming each individual part works.​

​Why did it work previously but then stop working? How can I get it to work again? ​

​What have I tried​​:​

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• ​Different USB C cables ( one of which was confirmed working by the technician when he visited, the other cable works also)​
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• ​Different laptops (technician replaced system board on one XPS 7390 2-in-1, Dell sent a replacement 7390 2-in-1, I bought a Lenovo Ideapad 5. My older XPS 9350 works as expected, but newer laptops don't appear to work on a Dell or generic USB C monitor?​
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• ​Reinstalled Windows.​
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• ​Installed all Windows updates​
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• ​Updated BIOS (also confirmed BIOS settings as per Dell support)​
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• ​Chipset drivers, and all other drivers suggested to me were updated. ​
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• ​I contacted DisplayLink and provided logs and they said neither of my monitors use DisplayLink technology. Dell support told me numerous times to download DisplayLink drivers (I tried this anyway, but it obviously didn't work)​
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• ​Different order of connections & turning on monitors, connecting cables, different ports (right and left on 7390)​
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• ​MST Setting on P2219HC monitor.​
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• ​Choosing the correct source (usually auto detected anyway) on monitors. ​
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​Thanks for any help provided but I suspect it will be a long time before this one is resolved.​

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