WD19DC with 2 USB-C cables swap

@GeneG33433  The WD19DC's documentation, specifically this page, indicates that the cable can be removed, but that entails removing the entire interface module.  I don't know its part number or how to get it, but it does seem achievable.  It might be expensive though because there are some electronics in that interface module, which among other things make the difference between whether the dock supports Thunderbolt 3 (WD19TB) or just regular USB-C (WD19 and WD19DC).

That said, the WD19DC only ships with the dual connector cable.  The "DC" in its model name literally means "dual cable", so I don't understand how you could have ended up with WD19DC that only has a single connector cable, unless somebody else took the dock's original cable and replaced it with a single cable.  It also comes with a 240W (not 240V) power supply, so if you don't have that either, it sounds like you didn't get a WD19DC in the first place.  Did you perhaps get a regular WD19 or a WD19TB even if you actually ordered a WD19DC?  I remember there was a two-week period recently where I helped at least four separate people here who were wondering why the WD19TB they ordered couldn't run display setups that it was supposed to be capable of running, and in all cases within that short period, the answer was that they had ordered and paid for a WD19TB but had actually received a regular WD19, which only supports USB-C rather than Thunderbolt 3 and therefore couldn't run their display setup.  In all of those cases, exchanging the dock for an actual WD19TB resolved the problem.  If something similar may have happened here, that's what I would consider doing first.

I made a mistake, it is actually WD19TB. 

a reason I asked the question, was that the company I work for was replacing 7520 with 7550 and i7 workstations came with dual USB-C's WD19 DC. So I was guessing that probably for more power hungry 7550/Xeon dual power USB-C may be a must.

@GeneG33433  Ah ok.  In the Precision 7x20 days, Dell didn't have a dual cable dock at all, so Dell's guidance at that time was to connect a Thunderbolt dock and the system's own power adapter.  Then the TB18DC was introduced alongside the Precision 7x30 models, and the TB18DC has since been replaced with the WD19DC.  But the WD19TB only comes with a 180W power supply, so if you'd have to swap both the power supply and the control module to convert that to a WD19DC, it might be more cost effective to just buy a WD19DC in the first place.  That's especially likely if you take into account that in that case, you'll still have a full WD19TB left in order to sell, keep as a backup, donate, etc., rather than just having a WD19TB control module and a 180W power supply.

Running Xeon processor requires 180W on the USB-C, meaning that you have to power WD19 with 240W. 

@GeneG33433  I'm aware of that, but I'm not sure what that has to do with anything I said in my previous reply.  My point was that if you have a WD19TB at the moment, with its associated power supply, it might be better to simply buy a full WD19DC, which will come with a 240W power supply, rather than simply buying its control module and its power supply as parts.  Even if buying a full WD19DC costs a bit more than those two parts, you will at least still have a full WD19TB left over to be repurposed, rather than only having the WD19TB control module and 180W power supply that you replaced, which are not useful on their own.  (Well, maybe the 180W power supply could be put to good use on its own somewhere, but not the control module.)

@jphughan  OK, my question is: I will run WD19TB with 240W power supply to satisfy Xeon processor on my 7550.

Do I need that DUAL USB-C cable like used on WD19DC, or just one USB-C will be sufficient. Let's take a side a financial aspects of that mod.

Thanks

OK, I am powering my 7550 with 240W power supply and WD19TB and I have a yellow warning sign on my power ikon. 

How can I get rid of the warning sign?

@GeneG33433  I just told you in my earlier reply that you needed the dual cable solution.  I even explained WHY you needed the dual cable solution, namely because of limitations around the USB PD spec max and even around Dell's stretching of that spec out to 130W.  The WD19TB can only push 130W because it uses a single cable.  The WD19DC introduced a dual cable design for the express purpose of being able to push up to 210W -- but you don't have that dual cable.

I just tried to reboot my WS and it put me in a choice to continue or go BIOS settings. I went into BIOS and checked under Thunderbolt ability to boot or something in that manner. When I rebooted it got me into the same spot. So I have to do something...

@GeneG33433  Based on your previous question, it sounded like you were asking how to get your system to actually power on from full shutdown from the dock.  My answer was for that question.  If your boot process is halting with a choice for you to press some key to continue or press some other key to go into the BIOS, then there should be a line of text explaining why the boot process halted.  What does it say?

@GeneG33433  You shouldn't have to change anything.  As long as the WD19DC was plugged into wall power BEFORE you connect the system, you should be able to use the WD19DC's Power button to start the system.  The reason I mention that caveat is that some people who disable their electrical outlets overnight or whatever find the next morning that they can't power their system on from the dock.

What BIOS settings do I have to change for my 7550 to be started by WD19DC? Thanks

It opens SupportAssist/Onboard Diagnostics and says: Your dock connection has limitations. To continue operating normally, your system may draw power from your system battery. ..both cables are connected...

and they are both in and lit.

@GeneG33433  If you've got a 240W power adapter connected to the dock, then my only guess is that there may be a problem with the adapter.  One of the symptoms of a Dell power adapter going bad is that it starts being identified as an Unknown wattage power source rather than identified by its full wattage.  Somewhere in your BIOS, possibly under the Battery Information section, you should be able to find information about the attached power source.  What does it say when the dock is connected?