Dell Precision 7550 and 7750 System BIOS - 1.24.0 Breaks Docking Station USB C

Has anybody tried [1231].exe /forceit as admin? I don't want to have to request admin rights if that is a dead end.

@JamesCT​ Unfortunately it's not going to work. Even with downgrade enabled, Dell has extra security on some BIOS updates to outright prevent rollback which I believe is the case here. From the BIOS update download page:

Important Information

- Once the BIOS is upgraded, you cannot downgrade the BIOS EXE/Recovery (RCV) to earlier versions. BIOS downgrades are restricted when there are security updates and important fixes with earlier versions that impact the functionality of the system.

And when trying to downgrade the screen after reboot says it can NOT be rolled back. Seems hard coded to outright not allow it regardless. 

@danteoz​ Exactly what I encountered when I tried to roll back to the previous BIOS update. You would think that when they release a BIOS update and lock it down to prevent rollbacks that they would test and make sure that the new BIOS didn't mess up anything, such as docking. WHERE IS DELL SUPPORT ON THIS?!?!

Dell says that the fact that this post exists means that there will be people already working on a fix. I called them and they added me to a ticket supposedly. 

Same here. Unfortunately it is not possible to downgrade BIOS to 1.23.1 :(

So I just updated through Dell CommandUpdate and had the exact same problem, then found this thread afterwards :(

I had to shut everything down, disconnect WD19DCS, then plug in the "standard" charger that comes with the laptop.  I can now use my stand-alone laptop without any error lights and the battery charges, but I can't use the dock so I lose my dual monitors and all attached peripherals.

DELL -- THIS IS NOT ACCEPTABLE!

I work at a company that has THOUSANDS of 7750's in use.  I will be trying to get the message out to NOT run CommandUpdate and install the BIOS update, but there is no way I can keep everyone worldwide from doing it (I am a single user who is not in our I.T. dept).

I have the same setup 7750 + WD19DCS. It's really the worst system I ever had. Monitor issues, usb issues, networking issues, now power supply issues. All linked with the docking station. We are paying the premium to avoid issues like this. Surely it can't be that difficult to test before rollout the update!

VERY DISAPPOINTED. 

@JamesCT​ I tried, it doesn't work.

Same Problem here on a 7550. I'm already in contact with the support team. DELL proposed a board swap but i want to wait until they come up with a corrected BIOS. (There is a RAID0 build in and and I do not want to risk a restore when this can be fixed with an BIOS Upgrade). Problem was replicated with a second WD19DCS. Both docks work fine on a XPS15. Fortunately external 4K Monitors are working and I will not change my configuration for the the next days. Waiting for DELL to come up with a solution.

Hi all,

The BIOS version 1.24.0 has been pulled down.

The current workaround is to Unplug the Dock, connect 130W or higher wattage adapter to system first and plug the Dock again.

We'll let you know as soon as we get a new update on this.

Thank you for your patience. 

@DELL-Nathalia M​ 

Work around didnt work for my 7750 on 1.24.0. Is it supposed to light up both of the USB plugs from the dock if you have the additional power supply connected to the barrel plug?

@DELL-Nathalia M​ 

Thanks for that workaround, but it still doesn't fix resolution on dual monitors.  You still get varying resolutions on the monitors connected to the WD19 docks (1 only recognizes lower resolution).  But at least we can now use all peripherals connected to the docks.

@bbogedin​ 

For me it only lights up 1 of the USB plugs, and only gives low resolution on 1 of the monitors.

@DELL-Nathalia M​ my 3rd monitor (HDMI) still does not work with this method. The 2nd USB-C plug light is still not on.

Two of my monitors (DP) at 1080p 60Hz, ethernet, and all USB peripherals now work.

Thank you all for letting me know the workaround doesn't fix the issue completely. I just sent a note to the responsible team. 

Will update you as soon as I get a reply.