Hmm ... unfortunately diagnosing hardware issues reminds me of diagnosing bad subs ... there are just so MANY things that can go wrong! 
Luckily you've got three things in your favor: the problem manifests pretty quickly (versus a true Heisenbug that never shows up when you're trying to catch it), you've got someone who's able to spend some time fiddling with things (versus a plane trip) and swapping things out doesn't entail five figure bits of kit ...
In your shoes, I would first install the USBDevTree utility on your remote computer and see just what your topology is and who's talking to what ... you can do that remotely, and it will also do some simple diagnosis of the equipment ... that might be enough to get some info there. Make sure you identify at least one USB 3 port on your computer ... you can install it on your laptop at home first to build confidence in it ...
Prior to going onsite I would bring some additional kit: several different brands of USB 3 hubs (4 port, one Belkin, one Anker and one StarTech) and several brands of USB 2 hubs (same mix). I would also bring down some *good* USB 2 and USB 3 cables (you want the shielded stuff, ideally with ferrite beads but shielded is good ... you want the big, thick, beefy stuff with the stranded metal jacket). Make those cables just a short as possible that will still work with your rig topology. I would also get some good power supplies for each thing that is going to draw power: the camera, the hubs, etc (the camera power supply should be good, FLI isn't going to give you a $5 toy with an $11K camera but the other power supplies might be dodgy. You want the power supplies that are big, heavy and expensive [https://www.amazon.c...ly switching 5v], one for your USB 3 hub and one for each other thing in your mix ... I would also bring a USB 3 optical gaming mouse [https://www.amazon.c...rds=usb 3 mouse] ... luckily all of that can be bought and shipped for a few hundred ...
Onsite, first unplug everything from the computer and identify the USB 3 port. Plug the USB mouse into the port to identify it and make sure you see the mouse as USB 3 in the utility, then plug the camera into that port with the camera power supply with one of the big, beefy USB3 cables and see if it's happy (take a bunch of flats, download, etc.), and watch to see if USBDevTree makes any noises. If that works, then plug the USB 3 hub into the port, again plug the USB mouse into that port on the hub to make sure it's working and then the camera into hub (again using the shielded cables) and once again see if it's happy. You may have to move plugs around different ports, the internal topology is rarely what it looks like from the case, but basically you're going to be redoing your topology using the beefy power supplies, beefy cable and different hubs while watching the utility for funny stuff and hopefully at the end of the mind-numbing permutational trials you'll have enough info to bin the camera, bin the hub(s), bin the cable(s), bin something so you can then hook everything back up and you're good. There will be one more thing to watch out for, when you're doing your cable routing make sure that data cables don't run parallel to power cables (you'll potentially get "inductive coupling", usually not found with DC current but 'ya never know, can't hurt!), if they do you can shield them with good 'ole aluminum foil wrapped around the power cable where it's next to the data cable, or give them about 3" of distance ...
Good luck! It will probably be as much fun for you as getting my HyperStar field to be flat is for me!
Edited by choward94002, 24 September 2018 - 08:21 PM.