I'm not with DELL, so the real answers/support will come from them.  Just anecdotally on my end, my WD19DC dock works pretty well and reliably with my 7740 Precision laptop.  I vaguely remember some issues like the ones you note (i.e. only one of the cables "lights up" when connecting, followed by power warnings) early on, right after I received the hardware.  But I haven't had such issues more recently.

One thing to check: make sure not just your BIOS, but all other DELL drivers and software is up to date.  (e.g. use the SupportAssist application, or the Precision Optimizer, whichever is most applicable.)  For instance, there are Thunderbolt Controller drivers, Thunderbolt Firmware, chipset drivers, etc...

Another thing to check: make sure you're not sharply bending or pinching or twisting the cables connecting the dock to the laptop.  USB-C cables, in general, tend not to be very tolerant of tight-radius bending, twisting, etc.

Beyond the above, you might just have gotten a 'lemon' hardware-wise (either your laptop, or the dock...), which might be fixable via a simple exchange.  YMMV...

Thanks for your reply. The first thing I always do on new deployments is update firmware/bios/drivers. In this case I used Dell Command Update (I believe that's what it's called) which updated various drivers including the BIOS. There was no firmware update for the dock, even when checking via support.dell.com and with/without entering in the service tag number. 

I've updated the Thunderbolt Controller Drivers, but I cannot update the Thunderbolt Firmware. The system hard locks and the fans go to 100% (extremely loud). I've tried this numerous times and ways (undocked, plugged into normal power, docked and power connected to laptop, docked only, on battery, etc). No matter what I do, it simply hard locks every single time as soon as I open the firmware update software (not even getting to the point of clicking "update"). Not sure what's up with that. 

Just a moment ago, I "power drained" the dock, plugged it into power, plugged the USB cables into the laptop and both lit up. I attempted to power on the laptop but it hung on a black screen and fans went up to 100%. I had to hold the power on the laptop for 10+ seconds to power it off, the 2nd attempt booted into windows and all seemed well. While in Windows, I unplugged the dock from the laptop which switched to battery (as if the CEO was taking his laptop to a meeting or something) and plugged in back in a couple minutes later and only one lit up, tried unplugging, replugging, same thing. Tried flipping the cable over (not that it should make a difference) and same thing.. sometimes one side lights up, sometimes the other, sometimes neither, sometimes both. I tried shutting off the laptop and powering it back on and of course I get the BIOS dock/battery warning message. 

I let it power up and once it's in Windows, the laptop keyboard doesn't work, only catches every 4th or 5th key I press... I unplug the dock (which switches to battery) and keyboard works fine. I plug the dock back in, one side lights up, keyboard works fine but windows gives the warning about not enough power. 

This thing is a nightmare... we expected much better from a $6000+ laptop/dock combo. 

@OmniBoris : are you using the SupportAssist application instead of the Dell Command Update Tool? If yes is it coincidence or are you having trouble with Dell Command Update?

@CelticDubstep : Which Bios is the 7540? We have issue with low power message on boot up Powersupply at WD19DC is 240W and both USB-C cables are connected. And the laptop has networks connection loses once in a while. Today we updated Bios to 1.6.0 hopefully this helps. 

@White_Ninja - As soon as the laptop arrived, I ran Dell Support Assist, Dell Command Update, and Windows Update to ensure the system was completely up to date. It did update the BIOS to 1.6.0 during this. There wasn't any updates for the firmware of the dock, even when manually looking up the dock/service tag on Dell's Site. The only drives was for Audio and Ethernet which are already installed. This isn't a thunderbolt dock, but I updated the thunderbolt drivers regardless. However, I cannot update the firmware for thunderbolt as the utility hard locks the laptop upon launching it (before it even gives me an option of updating it) and the fans spin up to 100%. I have to hold down the power button on the laptop for 10+ seconds to get it to shut off and reboot. I tried downloading the firmware 4 different times and it hard locks the laptop each time, so I'm not sure what's up with that. 

This laptop and dock is unstable at best and at the moment, it's a paperweight on my desk because it cannot be used in it's current condition because it cannot be deployed to the end user (who happens to be the CEO) until it's working correctly. This was the first Dell Product our company has ever ordered and will be our last. 

@White_Ninja : Dell Command Update is supposedly deprecated, and shouldn't be used.  SupportAssist (current/latest version as of this post: 3.4.0.200) and/or Precision Optimizer (6.3.2, currently) are the tools to use.  In my case, I use mostly SupportAssist (Precision Optimizer needs to be "Run as Administrator" in order to use its "System Updates" tab - which is relatively more of a nuisance...)

@CelticDubstep : Wellp, don't know what to tell ya.  I see lots of similar complaints in customer reviews on Dell's product page for WD19DC.  For some odd reason, it works 'reasonably well'** for me - but apparently not for quite a few other people (including you.)  At this point, you want to get in direct touch with DELL support, to see what they can come up with (I assume for an expensive machine such as the one you have, you ordered some sort of a support plan?  if not... you should have )

** reasonably well - meaning I only get an occasional on-off flashing of the keyboard backlight for no apparent reason, or the main display occasionally turning off, then back on again when docked and sitting idle under lock screen for a while - but I'm not sure those issues are specifically being caused by the dock, as opposed to something else...  As with all new systems, I expect stability to incrementally improve with future software updates.  But again, YMMV

@OmniBoris : OK I ll have a look at support assist. But I guess Dell command update is still supported and it gets updates regularly. Last one was to Version 3.1 in late 2019.

Does anyone else miss the integrated dock connector on the bottom of the laptops? I sure do.  The feel of the click when docking made me confident it was attached. And in all the years using the C, D and E series docks, they were very stable. The change to USBC is IMO a horrible idea.  I know the benefits of USBC but in 20 years of working on enterprise systems, plugging and unplugging into any port never lives up to the usage after time.  USBC is supposed to last 10K plug/unplug cycles. So you tell me, how long before the charging port on your phone shows wear? Just my thoughts... 

the usbc will last long enough to reach end of life cycle (at least) and with the ever changing field of technology that's all we're looking for in an enterprise environment.. It could be USB-C today and USB-tomorrow . I don't miss or not miss the plop-down docks, even though they were simple and easy to use. USB-C is (almost) just as easy, although the need to install a driver is now there.. but no biggie.

To note though, we're suffering issues with this WD19DC as well. Hooked into a Precision 7530 with intel's i9-8950hk and a quadro p1000.. The dock will literally go into 100% fan usage every 30 minutes, even when PC is idle. The dock is cold to the touch when it happens. Calling these docks defective is probably not the case.. I'd bet that it was an oversight in design or an inheritance due to poor design.

It's also worth noting that there are DPTF chips in these laptops we have.. Intel's thermal dynamic framework chips are notorious for causing thermal throttling for no reason and massive fan usage in similar circumstance.

I wonder if it's relating to the behavior..

To OP: What's your security setting within bios for thunderbolt? I find Dell's docks work terribly with user security selected and advise to trying with the no security setting applied. Our dock seems to work fine, power draw is fine (no warnings and both usb-c LED's are on)

I'm not sure of your model of laptop as well but does it have both usb-c ports available to draw power from? It may be that your laptop is expecting the full draw through 1 usb-c port rather than the two that the dock supplies..

I have a similar tale to share regarding the TB18DC (audio would distort, requiring a power cycle sequence - a careful and complicated power cycle sequence, PC, dock, unplug, dock, PC) to recover.   But at least the TB18DC would power two 4K monitors at 60Hz. 

This was replace with a WD19DC to solve the audio problem.  Now this one won't drive two monitors at 4k at more than 30Hz.

Dell manual for the WD19DC states on Page 18 that my Precision 7730 with AMD WX7100 GPU is supported at 2 x 4K @ 60Hz via the DP interfaces on the WD19DC.

Dell have now sent me a replacement WD19DC that produces exactly the same behaviour.  I raised an SR for this on March 4th and have "ProSupportPlus" and we're getting nowhere.  Beginning to think the manual is just wrong, or there is a design defect in the WD19DC and nobody at Dell wants to say so.

I had a bunch of these laptops and the docks for a few months and just started to deploy them as my inventory ran out. I had the same issue after I had deployed this to another branch office. I already update all drivers and BIOS before they leave me and what eventually fixed it was the dock firmware. 

https://www.dell.com/support/home/en-us/product-support/product/dell-wd19dc-dock/drivers

download the firmware utility and do the updates. I had 2 of 4 updates in that utility that showed it was old. (first one on the list and the last one with the "ec") after this I rebooted the system remotely and it came back after a minute where I would usually have to tell the user to acknowledge the warning so I could see it on my side again.  

EDIT: 

FYI I had BIOS 1.10.2 which said in the notes it was to fix the power issues etc. but that did not work. Make sure you have the latest BIOS and any Thunderbolt updates in Dell Command Update before doing this dock firmware update. 

Just had a customer with this exact problem on a 7540 and WD19DC dock.  The WD19 doc firmware update fixed it, thanks for the link!

Trust Me These docks are total save yourself a lot of IT time and move on no generation has been fixed and We have had the 18s now 19s they both exhibit the same behavior and have costs us hours of IT time with no resolution and customers lost time and considerable amount of money. Do not do it unless your a glutton for punishment.

Similar problem, with the dock station plugged into the laptop power adapter which is 180 Watt it says you need a 180 Watt power supply. ( I don't have the 250 Watt one as it was not supplied by the IT department)  Also only one of the lights on the two USB C connectors lights up.  The keyboard on the laptop goes into lag mode at times where you can not type at 5 words a minute to get it to recognize all of the key strokes.  When the docking station is unplugged I can type at 70 words a minute with no problem (except for a few spelling errors) .  What gives with this setup. It is a brand new laptop and dock station purchased in March 2021.

The laptop is totally unusable with the dock station plugged in.

@Douglas C  When WD19 dock family models have a 180W power supply connected, they only pass 130W through.  The dock reserves some power supply capacity for its own internal electronics and to provide power to any USB peripherals you might attach.  The WD19DC always and only comes with a 240W power supply, so I'm not sure how your IT department could have ended up with WD19DC dock units and not the proper power supplies to provide along with them.  But the reason you're having trouble is because you're not using the intended and supported setup.  You're instead using the WD19DC with an undersized power source.  If you had the correct power source, the WD19DC would be able to pass up to 210W through to the attached system.  I'd suggest contacting your IT department to communicate your issues and your expectation that they'll give you the right equipment.