Having the same problem. Tried to downgrade to BIOS 1.0.7, but it didn't roll back every payload and so didn't restore functionality to my USB-C-to-HDMI adapter.
To say this is an inconvenience when I am WFH every day is an understatement. I'm amazed Dell are taking so long to acknowledge, let alone fix, the problem. Does anyone have any idea of a workaround, or an ETA for a fix?
I received the CableMatters USB-C to HDMI adapter today and hooked it up, but as my luck would have it, I received a faulty adapter. Screen flickering and artifacts at any resolution above a 30Hz refresh rate replicated on multiple laptops. However, the XPS 13 *did* recognize it as supporting 60Hz - something that it hasn't done with other adapters I've tried.
In other news, Dell told me via Twitter DM that they're taking this issue to their Product Engineering team and will get back to me in 1-2 days. I'll post here when I get an update.
@faraday7 You might wish to twist the cable a little if it flickers, or try re-plugging it.
I noticed something strange yesterday. I was reading on some forum that some user mentioned it may be worth setting POST to “Thorough” instead of “Minimal” for better stability with an eGPU. I thought this could perhaps solve the problem, and indeed, I was finally able to get the problematic display adapter to work with my XPS 9300!
My joy was short-lived, however, as after I plugged it back to another laptop and then plugged back to the XPS 9300, it no longer worked again. And this time, it seems to be permanently broken on the XPS 9300 no matter what I do.
Update: Dell is being persistent about having me revert to BIOS 1.0.6 to debug even though folks in this thread have already tried doing that. They're also saying that they can't rely on this community thread as an indication of a BIOS issue due to "differences in scenarios" which is total <profane>. Please, if you're experiencing this problem, contact Dell
Customer Technical Support directly to make sure your voice is heard - then come back here to rant about it 😉
@faraday7 maybe you could revert to bios 1.0.6 as they say and do the debugging? Pretend that it works when flashing back to 1.0.6?
I have a video of two XPS 13 side by side with 1.0.6 and 1.0.10 here: https://youtu.be/tOgK5AbL8Eo
You can see the same adapter works on 1.0.6 but not on 1.0.10. might be worth showing them this.
I reverted to 1.0.6 as they requested, but the issue remained. The system was unable to perform a full rollback, but the BIOS portion was "successful". The Dell Customer Service rep has since asked for screenshots of my BIOS version, OS version/build, and Thunderbolt driver version to forward to their engineers.
... I should've bought a Mac.
@faraday7 yeah it's really silly and almost as if the engineers don't have spare XPS 9300s lying around to test the issue.
I guess just give them whatever they ask and emphasise that the PD firmware could not be rolled back. I really suspect the PD firmware is screwing with something. It's probably supplying insufficient power to certain adapters such that they no longer work.
Maybe could you ask them for a way to revert the PD firmware? (You can show them from the BIOS flash program that the PD firmware was not reverted). Then if you manage to rollback the PD firmware, you could then demonstrate that it works and the issue is really with the firmware update.
@describee What is the "PD firmware"?
I've hit a brick wall with Dell support, as they are advising me to reinstall my operating system to see if that fixes the issue. Talk about using a sledgehammer to crack a nut!
@AbbasBThe PD firmware basically governs the power delivery of the device. I believe it is linked to the "Main System TI Port Controller" firmware.
After flashing to 1.0.11, if you revert back to 1.0.7 or earlier, you will notice that the "Main System TI Port Controller" firmware still remains at 184.108.40.206 and does not flash back to 220.127.116.11. Here is a screenshot: https://imgur.com/a/vNZWuva
If Dell can somehow allow us to flash back the "Main System TI Port Controller" firmware to 18.104.22.168, I believe this would solve the problem somewhat. Maybe you could take a screenshot of your BIOS downgrade page and show them that you are unable to flash back to the old BIOS? If they can provide the piece of software to downgrade the "Main System TI Port Controller" back to 22.214.171.124, then it would be easy to demonstrate to them the issue by flashing the firmware back and forth and then taking a video for example.
Yeah I agree reinstalling the OS will probably not work (though I did try that myself as well just to confirm). But I mean, just go along with what they say and kindly inform them that it does not resolve the issue.
Unfortunately I just got my laptop replaced, and my current laptop doesn't yet have a warranty transferred over to it yet, so I am unable to contact Dell directly on this issue.
@describee Yes, you're absolutely right. I downgraded my BIOS back to v1.0.7 but that didn't fix the problem. As you noted, the Main System TI Port Controller 0 and 1 drivers/payloads did not get downgraded to the old version, strongly suggesting they are the cause of the problem. I did a google search for that driver which strongly suggests that it is related to a Texas Instruments USB-C port controller, which makes it even more likely to be the source of the error.
I have sent Dell Support the above screenshot and explanation and hope they can provide a way to roll back the Main System TI Port Controller 0 and 1 drivers to the 126.96.36.199 version, to see if that fixes the error that came in with the 188.8.131.52 version. I will of course let you all know if I/they find a way to do so.