c-attack

You incorrectly told them the product sticker had been removed.  This is like removing the serial number from a device.  In Turkey and several other countries, RMA is handled through the local authorized dealer who then does the exchange with Corsair.  However, that's not really relevant since you are not trying to swap defective fans for replacements.  There is nothing wrong with those fans but you would like to buy more, correct?
 
You were looking for the wrong fan originally and since it's no longer in production, the price has moved into the ridiculous stage before it disappears entirely.  I suggest looking for the proper SP-Elite series that are exactly the same or the AF-RGB Elite or ML-RGB Elite will also work here as all of those are 8 LED center hub fans.  The SP-Elite are usually the least expensive, but you will need to look around in your local marketplace.  Asking some support personnel half way around the world to track down a better deal for you seems just a bit out of touch.  

OK, I think that is going to be the port detection test mentioned above and I do not think you can avoid it.  On soft restart it does not do this since the device does not power cycle.  How irritating it is likely depends on the max speed of your fans.  2500 rpm is going to be noticeable.  You also see this sometimes when using a powered PWM hub connected to a controller.  The PWM hub may power on before the controller does and when there is no signal present at that instant, it causes the momentary fan spike.  
 
Solutions:  User side, none really I'm afraid.  You could move all your fans over to the MB, but in fact it may do that as well.  I have not used my motherboard for control in quite a few years, but that 12v test is standard for most any dual DC/PWM fan port and how it determines what kind of motor is on the other end.  Nearly all motherboard headers are dual PWM/DC now.  Some CPU/OPT are PWM only, but then have other restrictions making them lousy for case fan control.  Theoretically, Corsair could alter this behavior with a firmware change.  However, I suspect that has been considered in the past and they chose to make to do the auto-detect from cold boot (sleep unavoidable) in order to help users when they connect fans.  The other way would require you do a full power cycle and drain -> PSU off, disconnect, drain power, flip back on, start up in order to make it do a fan test and check headers.  We prescribe that as troubleshooting method when the auto-detect isn't properly picking up fans, but it's probably a step to far for the average user to puzzle that out on their own.  

That one is a known issue with both AMD and Nvidia cards. The origin was with Windows, but other monitoring programs have made adjustments to compensate. 
 
I’d start a support ticket and swap the white QL. No reason to wait until it gets worse and we do see this at times with the QL series. However, you might try to replicate the original fan issue using a different stress test like OCCT, cpu-z bench, y-Cruncher, or even Prime set to mild-moderate settings. AIDA has a tendency to get entangled with cue. This usually shows as bad data, like impossible highs or lows but sometimes results in loss of control or internal device errors. It may or may not do the flickering, but be prepared for someone to cite the Aida conflict as a cause and address it first. 

LL fans are old. This is not a version or module error. Under 8 led series, it should have an additional line with 3 LL fans. Go to Lighting setup and see if you can manually configure the controller for 8 led x 2 and LL x 3. 
 
There is no reason the controller should not detect the LL fans. PWM and RGB are separate functions, so error in one side don’t affect the other. 
 
***Take the system out of Murals mode right now. That might prevent the initial setup.  

That one won't work because the two ends are designed for a LED channel, like what strips and water blocks use.  it's an LED channel splitter.  The end of the H100x RGB pump LED end is going to be a "4 pin flat" Corsair RGB fan connector.  
 
I think the way to do this is use the included "motherboard ARGB adapter" then a second motherboard->Corsair LED channel adapter so you can use the LED port instead of the fan port.  Something like this.  This keeps you from having to use a splitter for any two fans, which makes them copies of each other.  OK for static or uniform effects.  Not so good for sequential moving patterns or waves.  You also will need to tell CUE what is on there.  I good match would be Hydro X -> XC7 CPU block.  That is also 16 LEDs like your pump.  

All your fans are compatible with the Commander XT. Your 4000X comes with SP-Elite fans and those are set as “8 led fan series”. The same fans come with the H100x RGB. They are very different than the original 2016 SP-RGB fans with 4 LEDs. Those are not compatible with other Corsair RGB products and were discontinued years ago. 

Since the radiator fans are connected to the lighting node core with the others, they will operate in that group.  That leaves the pump LEDs.  It is intended to connect to your motherboard RGB 5v header.  However, there has been a general issue with this and there is/was some type of problem with the adapter cable.  You need to contact Corsair Support if your cable does not work.  Possible 3rd party adapter will work as well. 
 
The Commander XT should be able to manage the RGB control for the pump, but that’s kind of an expensive solution with minimal upside. The one positive is if you want CUE fan speed control over the fans. The Commander XT would replace the lighting node core as the RGB controller in addition to becoming a PWM controller. 
 
 

A couple others users have mentioned this and all on AMD GPUs. Looks like something they’ll need to correct on the next release. No way to merge them in the meantime.  
 
You could pull all three out into 3 larger single blocks and discard the former shell. Not sure if that would better or worse for you visually. If you do this and don’t like it, delete the 3 graphs, then uncheck and re-select the two gpu entries in the dashboard.  That will return them the form above. No way to merge them then either. 

The hardware lighting is the setting for when CUE is not running. When you are there making a choice, it will demonstrate the effect but that’s not a real setting for software use. Hardware lighting effects save to the RAM automatically, but you typically can see a short 1-2 second delay as the effect is written to the module.
 
You need to use the yellow + in Lighting Effects to add a software feature layer. It should appear immediately. If you’ve already done that, chances are you are in the middle of a rgb software tug-a-war.  You don’t have any specs listed, but stuck on red is often the MSI RGB program taking control of someone else’s RAM. You need to enter that program and restrict its ability to do so. I don’t use it, but it’s probably masquerading as a “sync all” type of function. 

Flickering is a common result when one element in the series circuit is having an intermittent signal issue. When you have a solid break, the lights go out and it’s easy to see which fan is the problem. With flickering it’s more difficult and they all can exhibit flickering at the same time. 
 
If you’ve already swapped a RGB lighting hub (along with the LN Pro), this is going to be one of the fans. Based on what’s written above, it seems like fan #2 is the place to start. You need to test each of the fans on that controller in the #1 slot with a static white pattern set. One them is going to flunk the test. 

You only need the Commander Core that came with the AIO.  It is a 6 fan PWM and 6 independent RGB port controller.  You don't need the rest, but hang on to it for future use.  You must use the Commander Core since AIO power is routed through it.  The others do have any advantages over the Com Core in this situation.  
 
If you have the 4000D RGB version, your front fans on are SP-Elite which go under the "8 LED fan series" category in CUE.  If you have the standard 4000D, they look similar but are not RGB.  The fans from the AIO are the ML-Elite OEM model, which are also 8 LED center hub.  So far, so good.  These all were designed to work together on any controller.
 
However, it's the last fan that has me a bit worried.  The "SP-RGB" was the original 4 LED addressable RGB fan from Corsair.  It was different than everything that came after it and it won't work on the same controller as other types or on the Commander Core at all.  If you bought a SP-Pro fan, the RGB part will work, but it's a 3 pin DC motor and will not be controllable on the PWM Commander Core.  Hopefully it is another SP-Elite like the front of the case and then it's as simple as 8 LED fan series x 5.  The Commander Core will auto-detect fan type when connected and unlike the other controllers can manage mixed LED counts.  However, it cannot handle the RGB from that original 2016 SP-120RGB.  There still are some of these floating around out there.  

Try connecting the mouse via usb. If it does not automatically detect, quit CUE and restart the app. 

In the CUE Gear Settings -> Dashboard -> toggle on the hard drive widget.  It is off by default.  You may need to restart CUE after enabling drive monitoring before it will show.  

Go to Windows Settings -> Installed Apps and find Corsair iCUE.  Click on the drop down menu at the end and select "modify".  Follow the prompts for the repair installation.  Typically this issue is caused by some sort of corruption error on the install and this cleans it up.  The repair will not erase profiles or settings, so it's always a good place to start.  

Fan control for the H100i Platinum is through the CUE software.  Are there really two Lenovo fans instead the of the ML-RGB that normally come with a Platinum cooler?  
 
The fans are intended to be connected to a 2 fan splitter coming off the Platinum pump.  Builders and other manufacturers have a habit of connecting these to the MB fan headers instead.  The pump power comes from the SATA and the dummy 1 wire connector is there to satisfy the MB CPU Fan safety feature.  The fans can be moved either way, but unless there is a reason not to run CUE on the pump splitter cable and through CUE is the best way.  
 
I suspect there is a strange fan curve written the Platinum's memory.  Once you get CUE installed, it will automatically write over the prior with something more appropriate.  You also can edit it by creating a custom curve (Cooling and yellow +).  

The Lighting Node Core devices are serial.  If there is a break anywhere in the circuit, the lights go out there.  That means no skipping numbers on the hub and you must start at 1-2-3, etc.  If you broke the 7 into a different group like 4+3, that's fine, but it must be 1-2-3 and 1-2-3-4 on the two hubs.
 
The other possibility is that a fan in the chain has a dead LED and the signal stops there.  If you have two fans each in the 1 slot and they are both partially lit, that suggests both have an issue.  Try swapping a different fan into the 1 slot to test and move the suspect fans to the end of the chain.  
 
Presumably the CUE lighting set-up did not reset, but if you changed the balance between the controllers, you will also need to change the Lighting Set-up to reflect that.  QL fan x 4, QL fan x 3, etc.  

That H100 is likely pushing 10 years old, so I am not sure a burnt out LED is too surprising.  There's not much you can do about that.  Fans bearings wear out as well, but those you can replace.  I seem to remember the H100 used DC 3 pin fans, but double check and make sure your replacement(s) are the same.  

If you are not able to control it through the motherboard software, you may need to contact Corsair in regards to the issue below. 
 
 

The LC100 triangles were meant to be an internal decorative item and thus come with an LED cable and PSU SATA for power. It’s possible to find some type of adapter that turns wall power into 12/5v for the SATA, but then you still need a Corsair RGB controller to be able to set it and it requires the same. This was meant for a typical PSU desktop installation. 
 
It likely makes more sense to go with lighting elements that use standard wall power and a different means of control. Nanoleaf, HUE, etc.  

Specifically for the drives, there is an on/off selector switch in the settings that defaults to off. You likely need to turn it back on and usually restart CUE after to get those back up. 
 
GPU fans should be in the GPU widget with the temps.  If not, try deleting the gpu from the dashboard and re-adding. 

It’s the cpu fan header where you put the H100v2 connector. Fans and pumps don’t count revolutions the same way. The MB reads half the actual pump speed.  

You need to contact Corsair Support or carefully explore the eBay or other 3rd party market. It has to be a Commander Core. The Commander XT and Commander Pro do not have the pump power delivery connector. 

So normally you could consider some type of RGB main circuit failure or PSU 5v delivery issues, but they seem to work in hardware mode.  That rules out both and leaves software corruption or conflict as the most likely cause.  Any new RGB or fan control programs added recently?  Motherboard RGB programs are the more likely thing to cause this.  
 
The other possibility is some type of lighting file corruption which is why it only affects the software mode.  I think it's probably worthwhile to do clean install of CUE with the registry cleans.  Make sure you export any valuable profiles prior to starting this.  It will erase all prior file history.
https://help.corsair.com/hc/en-us/articles/360025166712-Perform-a-clean-reinstallation-of-the-Corsair-Utility-Engine-iCUE-
 

It should be swappable.  The cap is a thin plate bolted to the outside like a lens.  The original Elite Capellix models came with two interchangeable versions.  If you don't like that silk screen decoration, it should be a 2 min change.  

Yes. All the Corsair Vengeance/Dominator series have a readable sensor on the module. It can be read by CUE or any of the common monitoring programs. 

You won’t be able to notice a performance difference between the two fans. You can choose based on appearance. The A12 is going to be slightly quieter between 1000-1500 rpm because of the difference in blade design. Above 1500 everything is somewhat loud. 
 
Remember the pump speed you are shown is a running prediction based on the revolutions recorded in a 2 second interval. So if it records 73 revolutions in 2 sec, that’s 2190 rpm and 74 in 2 sec is 2220 rpm. These are small fractions of a very high speed device. No pump reads 2200-2200-2200-2200 every 2 seconds. That level of precision is not needed in a product like this nor does change the actual flow rate which is really what matters. A significant pump drop is several hundred rpm indicating the pump clearly slowed down, lost power, or is fighting against noticeable pressure (continued operation under expected speed).