How to Troubleshoot a Hardware Device
Before you get started with the actual process of troubleshooting any electronic device, it's imperative that you follow a set of rules to make sure that you don't cause whatever it is you're trying to fix to suffer an even greater problem than it already has. Troubleshooting doesn't always work, but there are some things you can do to make sure you don't make things worse.
#1: Never hit, bang, damage, throw, or otherwise physically harm the device you're trying to fix. It seems pretty obvious, but you'd be surprised at how many people choose to fix something by banging it on a table or hitting it with a clenched fist. Unless it's a proven method and otherwise stated within a guide, never cause physical damage to an electronic device.
#2: Properly connect and disconnect the device whenever applicable. Just because it's not working doesn't mean it shouldn't be treated as if it is, so don't just unplug and replug things at your leisure; make sure you properly eject the device first if possible.
#3: If you're not sure, don't do it. If you run into problems with a guide and you're unsure whether you're doing something right or not, it's best not to take the chance and just look elsewhere for a more descriptive guide. Another option is to post a comment on any particular guide and hope that the author reads and comments back.
Follow these three rules, and you're well on your way to getting your USB hub back in working order. Now, onto the guide...