Dead flash drives? What's going on here?!

After going through all of our members' answers to Paul's question, I noticed that the majority of them pointed out a common mistake that people make that can cause flash drives to fail - not disengaging the flash drives properly, by using the Windows "Safely remove hardware" process in the Windows task bar. Removing flash drives or other storage devices without using this feature can very possibly cause drives to fail, especially if something in the background is writing to it. I hope this isn't the case for you, but it's definitely worth bringing up. While this week there were a lot incredibly helpful suggestions from our members, including personal experiences of having a faulty drive and suggestions on troubleshooting the issue, one particular got me really thinking about your issue. What if your problem stems from a physical fault rather than a software-related issue? Hear me out. What if one of your six PCs has a physically damaged USB port, so whenever you plug one of your flash drives into this particular port, it causes physical damage to the flash drive connector--misaligning your flash drive connector pins or even possibly breaking the metal connection completely off? And in this case, you've used that particular damaged port with all three of your flash drives, physically damaging all the connectors on those drives and causing all three drives to be unrecognized in three different computers. I know this is a shot in dark, as it is with all troubleshooting suggestions, but it may be worth investigating. I'm going to stop here, as there is plenty of great advice from our members, and with so many possible scenarios that can cause flash drive issues, I'm hoping the advice here will help you get a good start toward solving yours.