Ok, a few things here: (1) The TC works "best" with "green" drives. Your Seagate Exos X16 is an enterprise-class hard drive, designed for high-performance and reliability in data center environments. The TC may not provide sufficient power to this drive, and maybe why it is acting as it is. (2) AFAIK, the TC's firmware can only support up to 3TB drives. However, I am aware that folks have been successful with using much larger drives. Regardless, when placed inside the TC, the TC's firmware will format it into three separate partitions to support its dedicated use for Time Machine. (3) Interestingly, some drives are particular on how they are orientated. As you are aware, the drive inside the TC will be in a fixed downward position. Whether or not this Seagate would have an issue with this, I don't know for sure. (4) Finally, double-check to see if this drive uses SMR. This is typical of Seagate drives > 4TBs. These are known to be problematic with the TCs. ... oh, and yes, although this topic seems...

Since you got these RAM modules from OWC, I would suggest that you contact them directly and have them assist you with this. I would think the first thing would be to double-check that these modules are the correct ones for your Mac. Your Mac also should have “built-in” instructions on how to properly add the additional memory and to what slots when using modules of different capacities. FWIW, I have been an OWC customer for years and have only had the best experience with their products and their support staff for things just like this.

As a general practice, when working with sensitive electronic components, you should make it a habit to use both a ESD wrist strap and similar mat. It only takes one static discharge to potentially cause damage. It sort of like the analogy of smoking while filling up your car with gas. 99.9% of the time you may get away with it, but the .1% can never be “taken back.”

@Dan Cronin If the base station does not show up in the AirPort Utility, give the following a try: (1) Temporarily connect your Mac or PC directly to the Express by Ethernet, and then, try using the AirPort Utility again. (2) Try using an iPhone or iPad instead. These tend to work “better” in finding a base station. Just use the AirPort Utility app. (3) Make sure that your Mac or PC is configured for a minimum of IPv6 Link-local only. The AirPort Utility relies on both Bonjour and IPv6 to discover a base station. (4) Try a “factory default” reset on the base station.

To be able to access the data on the Time Capsule's internal hard drive will require that you remove the drive from the base station. Then place the drive in a drive caddy or enclosure. Finally, connect the drive to the USB port on a Mac or PC. For there, you should be able to access the drive. Reemplazo del disco duro de AirPort Time Capsule Model A1409

See if any of the following articles can help: (1) Airport is warning of overheating - ASC (2) why is my airport extreme overheating - ASC (3) AirPort Time Capsule A1470 (Mini!) Teardown - iFixit (4) Repair AC version Time Capsule or Extreme - LaPastenague

No, you cannot use an SSD to replace the AirPort Extreme card in your 2014 Mac mini. Although, OWC offers "data doubler" kits to add a second HDD or SSD to a Mac mini, they do not currently offer a kit for the 2014 model.

See if any of the following articles can help: (1) How to troubleshoot Wi-Fi connectivity - Apple Support (2) Check for Wi-Fi issues using your Mac - Apple Support

The Apple AirPort base stations CANNOT extend the wireless range of non-Apple wireless routers. That is because they use a propriety method to do so with other AirPort base stations. However, the AirPort Extreme base station can "extend" other non-Apple wireless routers if the connection between them is wired. On the other hand, the AirPort Express base station can "join" an existing non-Apple Wi-Fi network as a wireless bridge to share a USB printer.

The Terminal command would be: sudo ifconfig en1 inet down