RE: Dell TB15 Desktop Dock - Step-by-step driver/firmware/BIOS installation instructions for XPS, Latitude and Precision notebooks
One tip I would like to share with the troubleshooting process. I, like many others, was getting a quick exit on the Thunderbolt firmware update because I had already installed it. But I suspected that maybe the installation wasn't clean because I don't know if I had the drivers updated before hand when I originally ran the firmware update.
So, I decided to see if there where any command line switches for the thunderbolt firmware buy running it with the /? switch. Sure enough, there was a /f switch that was described as overriding soft dependencies. I took a blind leap and hoped that this included whether or not the update was already installed.
So, I uninstalled every driver listed above, rebooting between every install. Then I also cleared out all disconnected devices in device manager. I then ran the steps one at a time starting with the BIOS update that I had already applied.
When it came to the Thunderbolt 3 firmware, I ran it from the command line with the /s (silent) /f and /l (switches). It took much longer than just running the executable previously and when it exited (I could tell by seeing when the process left the task manager) the log indicated that the firmware was updated (it didn't say anything about it being already updated.) So, I think that successfully forced it to flash again.
I then installed the remaining drivers in order. Rebooting inbetween each one even if it didn't prompt.
I then reinstalled the Intel graphics drivers followed by a clean install of the latest Nvidia drivers.
I then power cycled the dock and plugged it into the notebook without any devices connected to it. I let it install all the USB hub devices and then rebooted. I then followed up with the display, then audio, then USB hubs, then keyboard and mouse.
After ALL that, it seems somewhat stable. The display is no longer blanking out on me every few seconds, USB devices seem to be responding fairly well. I've been able to sleep the computer and wake it up while docked and have everything work.
Reboots while docked are still a little hit and miss. Sometimes it comes up with the login on my external monitor, sometimes it just completely blanks out both notebook and external screens until I unplug and replug.
Also, there is certainly a failure rate associated with plugging in the dock and having the notebook display work. Sometimes when I plug in the dock, the external display lights up but then the notebooks internal display freezes and doesn't act as a 2nd monitor. Usually unplugging and plugging back in resolves that.
Also, there's the high speed fan issue as well while docked.
At the end of the day, I'm still not happy. One shouldn't have to jump through such hoops to make a $399 accessory on a $2100 notebook function properly. I've already spent about 5 hours troubleshooting it to get it in this state and I still don't have confidence that it will remain stable long term. Dell should be packaging up all the necessary drivers and firmwares into a single install program that puts everything in the correct order. There are also still many bugs to work out with this thing.
I already submitted for a return last night because I was so frustrated with it (and I had only just received the dock 5 days earlier.) I may either cancel the return or wait until the last possible moment to return if I let it process through just to see if anything gets updated in the next week or two to improve the experience or to see if this remains stable long term. I'm cautiously optimistic right now.