XPS 9550: Latest Thunderbolt firmware upgrade destroys HDMI port

I just bought a TB16 for my 9550, and am going through the initial driver-update process. The first one I did was to update the Thunderbolt driver to yesterday's 4.26.03.001. The .exe ran, and came back with "Thunderbolt Firmware Update failed" dialog. The dock is NOT connected, I am just preparing the system to set myself up for success here. I'm not sure whether the FW update actually applied or not bc of the error.

After the update, I went into Win10 System Information, Software Environment, System Drivers, and see that "Thunderbolt Controller" Status is "Started" "Manual" "Running" "Degraded".

What would you recommend I do at this point? How do I check if the TB update really did not apply? Should I get the penultimate release and install that, then proceed with updating all the other drivers per the user manual? I intend to us the dock with a DELL U2718Q @ 4k60 (which should work with either DP or HDMI), 1g ethernet, and audio usb interface.

I already have latest BIOS 1.5.1. I'm running Windows 10 Pro Version 10.0.16299.

I saw the linked support page for the 9550, but am confused as to how to grokk it - i assumed it's point was to convey the "recommended configuration" however for each sw package/driver/component, there are several "recommended" items. What gives? 

@Timblaktu: I guess your problem is not related to the Thunderbolt firmware update we are talking about in this thread.

I have a TB15 dock and the new thunderbolt firmware works nicely with it. It is really just related to the laptop internal HDMI port.

Same issue here - dead monitor. How can I send you PM?

Dell-Alasdair, Same issue here. How can I send you a PM?

This firmware update rendered one of our XPS 15 9550 laptops unbootable.  The update progress bar reached 100% and prompted for a restart.  I clicked OK and the computer never booted again.  It gets pas POST and the Dell logo but hangs at either a black screen or on the Windows logo with no progress.  Onboard Diagnostics still work and show no errors but I can't boot from USB or from the internal NVMe drive.

Unfortunately , I met the same problem with HDMI port on my 9560 after upgrading the latest TB firmware "Intel_TBT3_FW_UPDATE_NVM26_0CT6J_A03_4.26.04.001.exe". Now I have to wait a reply from DELL as I cannot use my external monitor.

Hey team, I'm having this issue also. XPS 15 9550 - same firmware update as you've all applied, resulting in the onboard HDMI port inverting colours.

Appreciate a solution, Dell.

Happy to PM my service tag to a dell rep.

I have the same exact problem.  I can't use my HDMI port at all anymore!  This is a huge problem.

Same with XPS 15 9560.....

Thanks for all the PMs guys. I won't be able to respond to them all but your details are noted. Our engineering team are investigating this and as soon as a solution is available I will post it here.

Thanks for your patience.

@Timblaktu - I have the same issue. Tried to apply it (have the TB16 dock) and it failed, but no reason was given. Although looking at the replies in this thread,  that's probably a good thing!

I am having the exact same problem.  My Precision 5510 HDMI port immediately became unusable after installing the Thunderbolt firmware update.  A huge problem.

I suppose I am lucky.  My XPS 13 9365, which is using a new firmware NVM 23 seems to be OK.

Thanks @oduis, it wasn't clear to me from the thread that the HDMI port not working for people is the laptop's HDMI out, and that the HDMI out on the TB16 dock (which is all I plan to use) works fine with the new Thunderbolt Firmware 4.26.03.001,A07. (please confirm/deny that _that_ is what you meant.)