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

7550 here, been trying to figure out why the ethernet and displays suddenly stopped working on my Precision through the WD19DCS dock. It works on an old Latitude 7490 I had sitting around, both network and video output. After hours of troubleshooting and trying to work on just the laptop screen, thinking it was the dock, Dell support (for docking stations) suggested I contact the Precision support.

Only one TB connection lights up and powers through the dock, whichever one is plugged in first, but no display or network any longer. Can confirm that 1.24.0 was just installed. Everything else is up to date with drivers and firmware as well.

Seems this BIOS update broke the TB connection. I don't have another dock or thunderbolt device to plug in and test.

I have exactly the same issue and its a major problem. Please provide a fix asap since this BIOS update is supposed to be Critical i dont really want to roll it back. 

Similar situation Precision 7550 with WD19DCS dock but fortunately monitors and Ethernet still work for me.  But boot-up pop-up about low power charger/dock and Windows 10 has a yellow triangle on the battery/charge icon saying "Slow charger".  Only one of two USB-C cables from the dock lights up.  It's always the first cable plugged in in any orientation, so it doesn't seem port or cable specific.

Happened on very first reboot after 1.24.0 Bios update installed through Dell's SupportAssist program. Happens on every reboot now.  Confirmed 1.24.0 is the Bios version from the dock pop-up.  Saw the Bios get updated on the screen and it said successful before rebooting.

Re-downloaded and ran the Dell Dock firmware updater (May 2023) for my dock's service tag from Dell website and all versions were current.  Dell's SupportAssist says no more updates.

Precision 7550, same issue. Was working fine, docked the system this morning and when it booted I received the update notification, applied the update and now only one of the 2 USB-C dock connections is recognized at a time and I receive the message stating that my connected ac adapter is low power. I tried to downgrade to the previous BIOS version and on reboot I received a message that applying the BIOS had failed because it was incompatible, even though I have BIOS downgrade ability enabled in BIOS. I guess we're stuck with the issue until Dell resolves it. Sounds like sloppy QC on the update testing with this many people immediately having the same issue. 

I had the same thing happen to my system.  I put in a request for a replacement motherboard with an older firmware because I can't wait for them to push out a new Bios to fix this issue.  Luckily,  I have another docking station.  Unfortunately, I now need to also keep my AC adapter plugged in because the docking station doesn't supply enough power

We have upwards of 30 users of the Precision 7550 /WD19DCS combination that are, or may soon be compromised by this fail. Please address DELL!!!!

Same problem here with Precision 7550, after this "upgrade" only one out of two USB-C ports is lit up at a time and Windows is complaining about weak charger. Two monitors work but the second one's resolution maxes out at 1280x720.

@rbtw4​ 

If you have an extra power adapter, plug it directly into the laptop to allow full performance.  That's what I'm doing in the meantime.

@Karl_L​ Thanks for the tip. I might just have it.

Same problem with my 7550.

We have also a lot of users in our company with Dell Precision 7550 notebooks.

Please provide a hotfix.

Same thing here. Luckily we only have 4 machines (all of which JUST had their 3 year big-dog warranty expire), but they are all affected. 

All 4 were updated before dock-based testing was done on my test machine. Oops. 

Curious to see if those docks that were hooked up while updating DEFINITELY still work with a machine that hasn't had the update installed. 

Where is the Dell support when its required?  Bad BIOS is still available. File should be withdrawn ASAP.

I replaced the WD19DC with WD19TB and laptop charger. Now I can at least use laptop and external displays until new working BIOS is released.

Dell Support? Can someone at least acknowledge the issue? 

Same problem; updated the Bios to 1.24 this morning. Suddenly got a battery low warning and saw that only one of the two USB-C plugs were lit up from my WD19DCS dock. The two monitors are still working but it's not charging sufficiently to keep the laptop charged.

Not impressed